I've been operating games since 2012. I know this will probably ruffle some feathers, but for the most part this is something you don't need to do. And I'm basing this is real world experience over the years, not pulling generic "advice" out of my ass.
That being said, ALWAYS replace the little 100uF cap on Data East and WMS System 11 power supplies. It also isn't a bad idea to replace the big caps that filter the 5v power such as the 12000 uF on the Bally SDB and the 18k uF one on WMS power supplies. But I'll admit that I usually don't anymore if the cap's capacitance and ESR tests good. And some small caps on sound boards and other areas seem prone to failure. Of course visually inspect the caps and replace anything that looks suspect, but replacing EVERYTHING is not needed. Get a good digital ESR/capacitance meter and save yourself a lot of time and effort. Yeah, the ESR won't identify every problem, but I've found it to be right 95% of the time or more.
One thing that is necessary is replacing the connectors for the 5v chain on WPC games. This means the connectors at J101 and J114 on the driver board and at J210 on the CPU board. It is also a good idea to replace the 0.093 connectors at the transformer plug that bring 9v AC up to the driver board at J101. Doing this significantly cuts down and usually eliminates reset issues for these games. Also inspect the header pins at these connectors, but I've found that they usually are fine and don't need replacement unless you have reset issues or they seem heat stressed.