It's also important to stress that ich and I are both referring to what might be called "technical" concessions. "Trade deals place limits on sovereignty" is more or less the only thing we are saying (as far as I can see), and it's clearly undeniable.
In the UK/Japan deal, for example, the UK (and Japan) agreed to ensure that they would maintain competition law to address certain practices (Article 11.3); agreed not to provide state subsidies in certain situations (12.7); agreed to allow the other party to complain about potential breaches (12.6); agreed to establish a Joint Committee with equal representation to oversee implementation (23.1), whose decisions are binding on each country (23.2), along with several specialised committees (23.3); agreed to subject themselves to various UN Regulations on goods (Annexes); and so on. Both sides also agree to drive towards regulatory cooperation and alignment. At least once it's also explicit:
"A Party shall, wherever practicable, defer to the regulatory and supervisory frameworks of the other Party." (Annex 8-A(9), emphasis added).
It's also notable that, at various points, the Trade Deal states that each side shall notify the other of various issues, complaints, etc "in English", so that Japan has conceded the point that English shall be the primary language of communication. It's a small concession, but it's still a concession on their part. Imagine if we'd been forced to communicate only in Japanese. I don't expect the Japanese mind all that much, mind (it's probably easier for them too!).
Anyhow, the UK/Japan Trade Deal runs to around 1000 pages. It's an agreement to work together. If you work together then you are ceding at least some level of sovereignty, clearly, because that means allowing the other nation to have some say and some influence in the decisions you make.