Sure if you play rock, paper and scissors exactly a third of the time you're not going to lose. However, if you're playing rock paper scissors vs a large group of people who collectively on average don't play paper very much then your strategy is going to be really suboptimal. Obviously you should play rock much more often than anything else and play scissors much less often. Nevertheless a trap a beginner might fall into is to play paper some % of the time as this is optimal vs someone playing GTO RPS. This is a gross simplification of my original pst in this thread. Newer players learning GTO might make this mistake lots in poker, criticising this mistake is not to criticise GTO per se.

Similarly, if someone is really bad at noticing when their opponent plays rocks too much because they've spent all their time learning optimal %s of rock paper and scissors vs someone playing a certain strategies then they might fail to exploit this. Say there's an opponent who always shakes a little before playing scissors, if you can't see this because you're a RPS noob who's jumped right in to working out these optimum %s then you're going to be playing badly vs this guy.

Not all of this is analogous to poker, just using it to show where I stand as the original flavour of the post seems to have been distorted a little.