Mostly agree, but a lot of thrift stores in the US have gotten significantly more expensive and lower quality over the past 10-20 years. You can blame resellers (like vintage stores) for at least the second part of that, but also fast fashion in general.
I have been to hundreds of thrift stores across the country. Rarely are any two the same. Rarely are they the same store if you visit it months later. And some are expensive but if they are, they usually have better stuff. Visit the stores in the areas that are generally poor and you will still find lots of hidden jems at deep discounts to the retail price. So much so that it's always worth the extended trip outside of your neighborhood.
Heck I have a some near me that I know as different places to look for things. One area is cheaper, one more high end goods, one tends to have older stuff, just because it depends on the people donating!
I cook a lot, I strongly agree with avoiding things that only do one thing.
That slapchop looks real handy, don't it? Wait till you gotta clean it. Any time savings are instantly lost, and now you have nooks and crannies for bacteria/detritus to hide in.
Look, generally speaking: if you don't see professionals using something, there's likely a good reason for it. Maybe you're doing something smarter than a pro. But that's rare, remember that.
Sometimes the reason the pros aren't using a thing is because they have spent 10 hours a day, 6 days a week for 20 years learning how to do it that way. Sometimes the tool is just more sensible.
You're right, sometimes it is. However, in a society whose existence is centered around consumption, beware the salesman. The point is to think about the purchase: most of the time you don't need it.
To add onto this, Goodwill is the worst thrift store, so try to poke around and find some mom and pop thrift stores. They do more good with donations and charge far less when you're buying (plus will usually help you out if you are really in a bind and need something)