tl;dr: alt-lite were a bunch of astroturfed fools who tried and for a while succeeded in subverting the actual "alt-right" into supporting mainstream conservatism, they are basicially dead at this point but might make a return under fuentes

First of all, despite this subs name, the "alt-right" is not a legitimate ideology. It is rather, or was, a coalition of non-mainstream right-wing and socially conservative (eg: nationalistic right-libertarians, Third Positionists, Christian traditionalists, etc) people who joined together in an effort to support Trump and other anti-establishment right-wing populist projects mainly based on opposition to the more overt "political correctness" that was arising from progressive liberalism since the early 2010s, matters such as immigration and feminism (then it was just third-wave feminism) and also neoconservatism. I'd like to add, I consider the alt-right as dead and only existing between 2015 until at-best 2018 and we're in a "post-alt-right" period right now. I'd say the anti-establishment right is making a return online, with new figures like Keith Woods, but its too early to say.

The "alt-lite" was just an astro-turfed group of online personalities funded by Jewish-owned and/or funded organisations, eg. Rebel Media and Breitbart News, whose sole purpose was riding the coat-tails of the online alt-right's popularity to subvert such anti-establishment sentiments and mold it into a online kosher movement which was basically just supporting all the tenets of mainstream conservative liberalism while also preventing and killing off the rise of an actual right-wing alternative. I personally could see this from the start when I got affiliated and started watching with this whole dissident right scene.

Its army of BASED degenerates infiltrated popular "alt-right" and anti-SJW online creator communities, using memes from "alt-right" strongholds like 4chan and embedding themselves as popular channels so that more authentic "alt-right" figures were either drowned out or forced into their sphere. One of their most famous tactics was one straight out of the subversive Talmudic playbook, utilise male sexual desires by putting some caked up harlots in revealing and tight-fitting clothing in front of a camera and have them repeat basic bitch talking points and target low-hanging fruit which would draw in loads of deluded young men (this is where the term trad-thot originates from). I'd say this was largely successful in diluting the original 2015-2016 alt-right message by the time of Trump's inauguration. This was additionally aided by the failure of Charlottesville, which weakened the more authentic alt-right and made "optics-cucking" the more popular option. Thus we saw the creation of alt-lite groups such as the Proud Boys, who stole the more activist types, and people wasting their time lining up as foot soldiers for mainstream conservatism. They even got their own "intellectual" in the form of Jordan Peterson.

In terms of their ideology, like I said they are basically mainstream conservative liberals who just utilises the edginess of the actual alt-right for their own subversive methods. They channelled concerns about demographics into solely opposing Islam, they channelled ethno-nationalism into the more generic, weak, pro-liberal "Western chauvinist" civic nationalism, they channelled anti-elite sentiments (specifically targeting a certain) into opposing just the "Regressive Left" and channelled the alt-right's original anti-leftism into brain-dead free-market GOP-onomics. Really, if anything it was more pozzed than the pre-2010 Democrats because it was pro-LGBT, pro-black and pro-degeneracy.

Thankfully, the alt-lite collapsed on itself between 2018 and 2019. I'd say it began with the revelations about Kraut and Tea and his little Discord group, then we saw the rest fall as all these fools started either being exposed as degenerates worthy of no respect which lost them significant amounts of support or they got into catfights with each other that killed their fanbase. What remained of the alt-lite by 2019 either merged into mainstream conservatism to become talking-heads for TPUSA or someone like that, became actual far-right or faded into relevance. And I'd say about the first case, regardless of your thoughts on him, Nick Fuentes and his 2019 "Groyper War" campaign did a good job weakening the TPUSA crowd. There's also the Proud Goys, under their Afro-Puerto Rican leader, who are basicially bound to be declared as a terrorist organisation and face mass-arrests anyday now.

The only relevant alt-lite figures left really are Paul Joseph Watson (who desperately tries to appeal to the more Third Positionist-kind of people), Styxhexenhammer (who was barely part of the alt-lite scene to begin with, he was one of the more legitimate content creators in the early days) and arguably Molyneux (I'd dispute how relevant he really is). However, even though they are basicially dead, there is a potential for an "neo-alt-lite". The grifter Fuentes and his groyper movement have got enough momentum, that some of the old alt-lite homosexuals like Milo, Millennial Matt and Baked Alaska have come out of their hibernation started tying themself to in addition to some neocons like Michelle Malkin. I've noticed since these figures returned, while never really a fan of him, Fuentes has moderated his message and stopped talking about demographics and Israel as much.