This answers the question then. You are not a manager if nobody reports to you. Tech Lead it is.
It sounds like you are filling a void on your team and doing a good job at it. Keep at it!
I’m going to kindly disagree with other assertions on this thread that titles are bullshit. There are definitely bullshit titles (like practically everyone at a bank being an Associate VP).
A title that reflects your level of responsibility is important when you move to your NEXT position. That is how you mark progression in your career. It saves you a long conversation explaining how your title was (for example) “Senior Software Engineer” but you were acting as Tech Lead or Architect.
I feel these pains daily. I also have a few senior engineers who are still drinking the Serverless Kool-aid (ex-AWS people).
AWS CDK could solve some of these problems but the platform isn’t really there yet. We have a few apps where we can run testing in CI or do local deploy/debug via Localstack. But setting that up was a massive pain, much more so than just running an old-school app in a debugger.