Granted, if it's a primary residence, you have your driver's license and neighbors to back you up. But what if it's an investment property? What if the squatters have been there long enough to have their ID say the address?
If you own the property, then that's public record and can be easily looked up. Once they verify you own the place, police are going to believe you if you say these people are squatters not renters, and they'll have trouble producing documents otherwise. I'd also love to know what percentage of squatters end up getting IDs with addresses to places they don't own, which also requires btw proof of residence (deed AND other forms like a utility bill with your name on it).
If that were true then land lords could evict someone just by calling them a squatter. More to the point, everything you're saying is about making a judgement based on evidence. Police collect evidence, courts make judgements based on that evidence.
I don't need an ID with a to turn on the gas and electric. Or, I haven't anywhere I've been.
I don't think it'd be hard to get an ID anywhere I can pick the mail, to be honest. I don't recall needing a document like a lease to get my last drivers license.
But then, I'm not squatting, and given that I try to keep a reasonable credit record and avoid court, I'm not disposed to start squatting.
It has been worse recently because of moratoriums on evictions (due to covid). In many cases, that meant that the people occupying the dwelling had no incentive to pay anything at all, and no process existed to remove them.