I’ve used those tools to pull an optispark LT1 and swap it with an 010 1970 350 in a 96 Firebird Formula. Also to remove/replace the transfer case in a 97 Ram. Also to pull the turbo from a 2009 BMW 750li. They don’t get used daily, but they’ve definitely not been babied.4 cars is nothing, It might seem like a lot to you and if you've had it for years and only done 4 cars, well TBH you can't use it a lot. I use my tools daily and need to do many thousands of cars/trucks/etc over time with the tools I have. A rusty bolt or nut using a socket/spanner that is not accurate would end up just rounding the flats off and the rathet mechanism would snap or wear out pretty quickly. Still for a low use user such as yourself, there's no need to spend loads on tools if they are mostly going to be sitting about for 99.9% of the time.
Any tool is only as good as you maintain it and use it properly.