Ok, based on (1) you only use the snippets on your Mac (you’re currently using Alfred, so no crossplatform needs) and (2) you only want to use basic snippets, I believe Keyboard Maestro is the best fit for you.
It does snippets with no visible delay (which is the thing bothering you on Alfred), it’s not on a subscription model (the thing you don’t want to get into with TE), and it’s super reliable (in two years it only failed to expand my snippets once, but I was doing some heavy stuff on a VM at the same time, so give it a break).