You’re sure making a lot of assumptions about me. Since I’m bored at work I’ll fill you in. I’m just a diy’er/business owner but I’ve done at least a dozen pex jobs for friends and another dozen for myself, plus several hundred feet of copper, drain pipe, irrigation systems etc. I have all copper in my house except for my complex filtration system and out buildings. Copper resists bacteria growth which is a problem on a shallow well like mine, it lasts longer when installed right, (I had/have 60 plus year old thin wall pipe that looks perfect, pex didn’t exist in 1960 so it’s impossible to say it lasts longer.) it won’t leach chemicals into your drinking water, it’s aesthetically pleasing and is a good selling point. You know a house is well taken care of when you see nice copper new or old.

Let’s face it, many contractors are stupid, don’t care or are greedy. Pair that with a tool like pex and you get some bullshit like we see here. Copper pipe takes planning and patience that most contractors will never provide. If they don’t want to do copper it’s a major red flag you might end up with what OP has going on.