Just more stuff to think about.
Used to be a mechanic--bought a lot of tools from Snappy on his weekly visits. Still have some sockets, wrenches, and a ratchet or two from the '70s.
Thin wall has been mentioned multiple times--it's absolutely true, the higher-end sockets tend to be thin wall which sometimes is the only way to remove a fastener.
Years ago Snap-on patented something call Flank Drive IIRC and it provided a bit more gripping strength--was incorporated into box wrenches and sockets. My newer combo wrenches have something like this on the open-end side as well.
A lot of the difficult aspect of professional auto repair is dealing with stuck fasteners--if you only work on new cars you won't often encounter 30 year old rusted bolts in inaccessible locations. A few things help get those stuck fasteners unstuck (aside from a torch, that is): 1) quality of the fit of the tool--closer tolerances don't permit as much slippage, which results in weaker grip on the flats of the nut or bolt head; 2) strength of the tool when you really really hurk on it; 3) 6 or 12 points--6 has bigger flats so more gripping strength; 3) comfort--as you put more pressure on it can your hand stand it? 4) alignment--if the tool (particularly a socket) starts to angle under pressure it can round off the fastener; 5) swing on a ratchet--ie how little can you move the handle and get a "click".
Amateurs who are repairing the old Chevy or restoring a wreck can encounter a stuck fastener and spend all day puzzling out how to unstuck it. A mechanic gets paid on flat rate--he/she is losing money with every second of screwing around. They'll pay for something that will get stuff loose quickly.
Screwdrivers: Wiha are nice, I like both them and Snapon. My snapons are the only ones in my screwdriver drawer in a fitted case, I don't reach for them first, I reach for them last

I hate the little hard plastic handles on screwdrivers (CMan have a bunch with these handles). I like the fat, soft rubbery handles you can really get a grip on. Some bigger screwdrivers have a hex-shape in the shaft next to the handle, you can press down hard while turning with a wrench--kind of like using a bit brace. Has saved my bacon more than once. I think I have one monster slot head screwdriver with that configuration.
Have broken Wiha and Snapon screwdrivers, had both replaced under warranty. Wasn't using as prybar, either, just bad metal I guess.
I currently have a dead Cman 1/4" ratchet and a 30-year-old dead Snap-on 3/8" drive shorty ratchet. It's so old the repair kit that Snap-on gave me won't work.
With C-man I can run the dead tool to Sears and I'm done. With Snap-on I have to hope that I see a truck in a shop when I'm driving by and have time to stop and talk to the dealer. Oh, yeah, I have to keep the broken tool in my glovebox so I'll have it... Maybe there's another way to get my stuff replaced, I guess I should check the web.
The newer C-man and SK tools are excellent, no complaints. So are some stubby combo wrenches I bought from Costco, probably made in China. I don't hurk on them, of course.
I have some odd-sized screw drivers that I don't use often but they get me out of jams. Once is a slothead (C-man) that's about 2 feet long. There was a particular screw on a car I had that couldn't be reached without it. I used it last weekend to adjust the carb on an old F150 without having to climb up on the bumper. I have a wide, short Cman slot head that I use a lot, it's also great for opening varnish cans. I have a skinny slot head that's rarely used as a screwdriver but is handy for getting dog poop out of my boot soles, digging out little crevices from goop, stuff like that. Every once in a while I find a tiny screw in a tiny hole that only this driver can reach. I probably have 30 screwdrivers...