First I think the main reason they want to push "good" people into management, is they are really short on good technically minded managers.
But mostly it comes down to the roles they provide on the ladder. From "principle engineer" which I achieved only a year ago after an age as Senior. That in itself was a fiasco. To get promoted I had to set objectives towards key skills and demonstrate at the principle level. However I was contracted full time to a customer as a senior and there was zero room to demonstrate any higher position. I tried to reach out to the team as a facilitator to see how that went and got it thrown back to me that, "Your not senior to us, why would we listen to you, in fact we resent it.", they typically added, "and lets not bullshit, we don't work for Company X, we work for "Customer Y", so your authority if you did have any is moot.
My senior at the time, holding the promotion from me said, "Paul, titles don't matter, it's how you work people that promotes you.", when I mentioned this to HR (yes it got that bad), their response was "Tell him to say that when he orders people around without his Senior Delivery Manager title and see how many people tell him to get lost."
Role is a triangle. You need the title and the authority to go along with the responsibility.
The career ladder, while it is supposed to have tech/non tech split, introduces many "key skills and values" at the next level up, which is Solutions Architect. There you are required to become a stakeholder in the management meetings, to be aware of delivery contracts, commercials etc. In my last 1to1 with management discussing career I pointed out, that from the 4 or 5 items listed as additional responsibilities and skills for architect, only one of them is technical (ownership of larger multi-team / multicomponent solutions), the rest are pseudo management tasks. His response was that the letter of the role is flexible. Going up, will not mean you end up in a desk job. I don't believe him.
At the moment I am in a kinda "custom" position, because I stated I do not want to do people management. I can't be technically honest while being people line manager and I don't have good people management skills either. So while normally a "tech lead" on a project would also be the "team leader" and possible "line manager" for people, I am not given the people management role.
I don't think they are trying to get rid of me, when they are allowing me to basically, currently, choose my own role. Also, I haven't asked for a pay rise, ever. However I get one every year. I didn't get one this year, but that's because they promoted me and... gave me a £8k rise for that. When I started paid, proper career in 2007 I figured a nice target would be a 2K rise per year. I've averaged more than that. Besides a fair salary, not stellar, but if the company do well and I do well, there is maximum 10% salary bonus. I have received that bonus every year with the company, all 10%.
To give you a slightly indication of the culture at the company which actually employee me. The first video call after they had bought the company, the CEO opened the video presentation by introducing the head of people and talent (a fairly fat woman) and saying, "we'd hear from her at the end of the call, she might even sing so we know it's over.". It took me a while, as that joke was not expected at all in a CEO company wide meeting, but, yes, he did make the "its over when the fat lady sings" joke. It's an Irish/UK company. I think I'm safe for a while yet.