Well that is lovely, except 1) I don't have a paper ID (and I do chuckle at your idea of telling citizens validly issued an ID card by their country that sorry it is not no longer valid because some bloke in the UK says you need a digital one now) 2) I would obviously enter the UK on my UK documentation as a UK national and 3) your various ramblings remind me you don't really know very much about this subject, but of course you are entitled to your opinions and I will defend your right to spout them irrespective.
1) people such as yourself doesn't necessarily mean you. I meant Italians resident in the UK that have paper ID, which I am aware is only some. If the EU were to want a deal they would have to make some compromises that deal with the security risks. The UK government seems happy with the status quo do its irrelevant.
2) Again, I didn't actually refer to you.
3) Do you understand the concept of speculation? You repeatedly make legalistic posts in various threads relating to international travel and then belittle members of the forum. I have replied to general posts in this thread, most of which are also not trying to advise people. Its an interesting topic and one where a lot has changed in recently years. There is nothing wrong with speculating what may change in the future.
Its fortunate that other members of the forum don't take this attitude in post below, when matters relating to their employment appear. I certainly don't.
This topic in some shape of form comes up regularly. The OP asked reasonable questions, and yet as so often there is so much conjecture that has no bearing on the actual law in the thread I don't know whether to laugh or cry (also some sensible and helpful replies). I have posted this already elsewhere but as a reminder, here is the law regarding Schengen entry for thrid country nationals, which now of course includes UK nationals: Other thread on EU entry.
Oh and on ID cards - the UK has long not liked them so has not stopped accepting them as is in its gift with Brexit (other than for those who validly used them for EUSS - that will be phased out though). To be clear the new EEA+ ones are biometric to a common standard so once all stock is those they contain the same essential information as the chip in your passport. On stamping and exit - UK does not do exit checks with limited exceptions - most traffic is via airports where there are none. It also does not do routine stamping other than for certain tiers of Visa - it is quite confusing for people as they need to know before the border if they need a stamp of not for the form of entry they presenting. For Schengen the stamps provide the physical proof of adherence with the 90/180 day rule so important to ensure it is done correctly - you are checked though against the Schengen Information System (SIS) and so there is a digital entry and exit too, which with ETIAS and EES will do away with the wet ink stamps and improve the information available and shared by SIS.
I have assumed based you how you write that immigration law relates to your current or previous employment. If so you might want to consider what rail staff could write about your posts in other parts of the forum if they wanted to be really critical...
If you don't have expert knowledge, perhaps you shouldn't be certain about what won't change and let others discuss?