Can someone explain to me why the T2 security chips are such an issue?

I want to take my 2019 MacBook air to MacOS 15. The only feature I really care for is the Phone Mirroring. Any solutions or any workarounds I haven't thought of? i used it via USB but the machine panics and kills it. The option to build and instal OCLP is greyed out in my software.

https://preview.redd.it/yh9cqtoj4fqf1.png?width=1318&format=png&auto=webp&s=449371d184e36221655b8f3e15f5b6500acc4428