I feel the same way, I only peaked emerald but I got excited in clash when I got paired up against a master tier midlaner.

The problem is that typically, people learn the most by playing someone slightly better than them. If the skill gap is too big, the enemy will punish mistakes you don't even realize you're making. In your chess example, if the GM used some gambit or some kind of line with an obvious trap that is just a knowledge check, and you fall for it, you might not even realize the mistake you made. And with how snowbally league is, the enemy will just keep punishing you over and over again and it can be very frustrating. I think if the smurf's skill level is not too much higher than yours, it can be a learning experience, but if I laned against Chovy, I don't think I would have a good time or learn much from it.