That's just a different way of saying some people like to play games where their opponent has no chance. So your "relaxation" comes entirely at the expense of others.
Single player campaigns are a better way to accomplish this because then you can do whatever you want as far as difficulty goes.
But what if you're a bottom 10% player? How non-sweaty is non-SBMM then? Is it not-sweaty to get absolutely demolished all the time even at your best?
Games and leagues where you're expected to try hard are entirely different. I'd say custom tiered PUG queues are much better than common huge pools, this way top players can filter people they're training and playing with. In the end I think I rather agree with the grandparent than not, communities typically feel more lively and diverse than blind ladders.