Is that a common thing to do? sounds extremely bad mannered and unprofessional to me.
You take an offer, start working at a place, then two months later you go: "Welp, sorry guys, grass is greener on the other side, I'll be going now. It's not you, it's that you use Angular and they have React over there. Screw you and the effort you put into training and onboarding me for the past 8 weeks."
Well, the company would cut you loose in a second if they felt like it.
A VP of Engineering at my first tech job was the first to tell me to never be loyal to a company because they will never be loyal to you.
Later the worst example of this I experienced was when I was a hotshot contractor at a medtech startup. About a week after I started, they pivoted and fired almost everyone except me and another recently hired contractor. Junior devs and most marketing/biz dev folks were offloaded. They were w-2 employees not contractors like me and my buddy.
Many of the folks there had been recently hired as the company was spinning up for a product release. They had been grinding for weeks to get ready for a trade show demo.
I found out about the pivot and layoffs when I heard some of my office neighbors crying.
I did some contracting as tech lead for a contracting agency and was very involved in the recruiting process. I advised against some recruiters recommendations for "hiring fast" when candidates were hot in the market or they accepted some hourly rates when I knew they could get better. If you want them to stick for a while make sure you're paying as much as they can get!
You take an offer, start working at a place, then two months later you go: "Welp, sorry guys, grass is greener on the other side, I'll be going now. It's not you, it's that you use Angular and they have React over there. Screw you and the effort you put into training and onboarding me for the past 8 weeks."
Am I out of touch or something?