People can claim to be seniors because the gates for getting that title are pretty permissive. But even if you had the conviction to re-evaluate yourself ("do I deserve to be a senior engineer?"), you'll find tons of opinions on what it means to be senior, what knowledge they should know, and what they should bring to the table before claiming that. It's difficult to build yourself a widely accepted roadmap.

You have to watch out for people being too exclusionary though, almost getting into no-true-scotsman territory.

For instance: you can be a valuable contributor to a large, interconnected system, explain each part of it, but maybe not have the skills to build it from scratch. I would call that senior, but I wouldn't say architecting it from scratch is a basic skillset of this position. My opinion is if you could build large systems from scratch for a company, I'd say you probably need a title and pay higher than senior.

If you did want to roll architecture into a senior job, I'd imagine the pay is higher than non-architecting seniors, but it's hard to quantify the architecture contribution to the salary's bottom-line. If you took the non-coding architect's salary and added it to the senior's most of us would be clearing like 300k.

Personally, I'm pessimistic around job duties because you'll find so many companies looking for do-everything one-man armies at lower-end wages.