Pi's themselves are random in quality. Some are very reliable. Others less so. That's what you get when you buy toy quality hardware.
We recommend used ThinkPads because they were originally $1,500 enterprise quality machines but they sell for less than $200 when entire fleets are sold off lease. I particularly recommend the 2019 E series because it has upgradable RAM to 32GB and two internal SSDs. You can't get that level of reliability and performance with Pi.