reddit, like any social media site, is reproducable. sure. but what makes reddit worth that much money is all the users engaging in blogging on reddit, generating huge amount of data at every moment. (so, in short, if it's removed in say, one minute after it's posted, one better save it in that minute or else one can never read what some users said.)

now, in principle only reddit has that data. so in principle, it can, say, change your data and make others think that your online personality said something you did not. though this is not true, as reddit won't go that low, they often delete posts and comments at their will, and a lot of times those deletions are just not reasonable at all. (edit: see r/undelete for a start) imagine you said something and just becasue someone on the internet does not like it, your word gets deleted. if you're democrat, you would remember how this content manipulation by bots on the internet swayed the 2016 election. if you're republican, you probably have fresh memory of how sites like parler and gab were attacked fairly recently.

the solution is to keep a separate online record of what people have said and done on your favorite forum. that solution is called a mirror site. reveddit is one of them. another famous site is called the wayback machine. now, if you were a big corporation like reddit, you probably would not like that idea very much. so in reality, these mirror sites are not really favored by big powerful sites and the groups running them. for example, there were two sites like reveddit, ceddit and removereddit, which worked pretty smoothly before. but when they stopped doing so, i have to search for a bit to dig up sites like reveddit. yet these mirror sites provide valuable record of what the conversation was truly like before a few people could delete potentially valuable parts of it.