Not sure if this is a "home improvement" topic, but I didn't see anywhere else relevant this would fit so I am going to drop it here.

I've lived in the same place for around 12 years now. Before I moved in, the place was owned by one other person for around 10 years. The place is probably ~20 years old. I have two toilets in the house. About 5 years after I moved in, the flushing mechanisms on one of the toilets stopped working and I inspected it and it looked like the bobber/float switch was busted to the point where when it got to max height, the water flow wouldn't shut off.

I pulled up a couple articles on the internet and it seemed like the parts were pretty straight forward to replace. So I went to Lowes, got the replacement parts needed and a few hours later, toilet was fixed. No big deal. About a year later the other toilet started acting up in the same manner so I just did the same thing. Both toilets had the original parts in them. They were all metal parts. The replacement parts were a brand called "FluidMaster" and I didn't really think much of it at the time. The replacement parts were almost entirely plastic.

So fast forward to today, and I have replaced the innards of the toilets on a fairly routine basis. It seems like every 18 months or so, I am having to replace the innards of the toilets because the float switch starts to fail. I came home from a day vacation on Saturday evening to find that one of the toilets was running and for god knows how long. I open the lid and sure enough, bobber is at the top, but the float switch hadn't disabled the water flow so the toilet just keeps running. I turned off the water to it and made a note that I'll have to go back to Lowes and pick up more parts. This will be the fourth or fifth replacement I've had to do on it.

What's going on here? Why are these float switches in these kits breaking so frequently? Does anyone else have this problem? Am I just buying the wrong parts continuously? Is there a better set of parts that I can buy to correct this issue?