My bringing in the comment about insufficient material was in direct response to your statements "For me, online chess should be as close to OTB as possible" and "But the same applies, the automatic draw that chess.com has implemented is wrong when one assumes it should be as close as possible to OTB and as such to the FIDE rules."
There are no arbiters so the site can't directly hew to all FIDE/US Chess rules and in some cases the rule from one federation is easier to implement programtically, though there may even be edge cases were that implementation fails.
The simple fact is, there is no way to stop clocks and call arbiters to rule on claims, so there isn't a good way to implement a pre-claim option and give the drawing move to meet the condition. Add to that the idea of premoves, clicking draw after the move doesn't always work (the way it used to be implemented).
The online format requires some compromise in rule adherence and even different federations have some differing rules. Again, the insufficient material rule; the US Chess variation makes the most sense, in my opinion, but the FIDE one works well with arbiters in place where they don't have to make any judgement calls.
I put this under Help & Support because for me as I look at it, something is wrong.
For me, online chess should be as close to OTB as possible. But for the threefold repetition rule, this is not the case. In OTB when a threefold repetition arises, basically there is a draw on a claim, play continues if there is no claim. But in chess.com after threefold repetition, the game is ended automatically with a draw!
The automatic ending is from my point of view not only wrong, as it does not exist in OTB but also bad. For example, when I have a winning position and my opponent makes a move which causes a threefold repetition. chess.com will automatically draw that game. But in OTB, of course, I would never claim the draw! I am not sure if you realize how bad this automatic draw is to chess!
The other way around also applies. My opponent is in a losing position, and I make a move which results in a threefold repetition. My opponent gets the draw automatically. In OTB he must be aware of the threefold repetition, is not allowed to ask anybody if the case (!) and if he or she misses it, I get away and can still win the game!
The same is to the say for the fifty-move-rule except that it is not happening often, that one has a winning position after fifty moves without capture or pawn move. But the same applies, the automatic draw that chess.com has implemented is wrong when one assumes it should be as close as possible to OTB and as such to the FIDE rules.
And beyond, because chess.com automatically draws after threefold repetition and the fifty-move-rule, the fivefold repetition rule and seventy-five-move rule, introduced six years ago, can never be applied. According to FIDE rules, for the first two, there should be a draw only on a claim, after the last two, there should be an automatic draw.
...But if you want to be as close to the FIDE rules, which is my expectation for a chess platform, the current implementation is wrong.
...The site is closest in implementation to US Chess rules. Insufficient Material draws are the most different from FIDE and is a slightly modified version of the US Chess implementation.
Regarding the draws by triple repetition and 50-move, it was a required claim for a very long time. I don't know all the specifics for the change but a couple of things likely led to it.
There are other things that don't align with FIDE. For example, you can't play premoves OTB. There are some things that fit better in online play, some due to implementation and due to complexity.