I think their point is the current GOP is behaving like they're members of a dictatorship in that they won't speak out or against their dear leader and allow him to easily break laws daily which they would have impeached Biden for in an instant, and have completely given up their job of governing in service to the leader.

Sure the USA is still a two party system right now, but unless something completely drastic happens between now and four years from now, I fully expect Trump to say "the Constitution says a POTUS can only serve two consecutive terms", and he won't leave office and the GOP will be completely fine with that.

It is an expression of fear. Just as democracies are well advised to take fears about immigration seriously, they are well advised to take fears about authoritarian overreach seriously (this used to be a core strength of the GOP). Many people fear the USA is on a trajectory of dismantling its democratic institutions and into an authoritarian single-party dictatorship.

If you are interested in a working democracy it would be wise to not dismiss these concerns out of hand just because they draw comparisons to historical regimes where authoritarian overreach ended democracies. The comparison might be wrong, yet the concerns are real.