I complain here and everywhere about the insane complexity in modern-day web app dev.
The truth is that, after you learn the 20 new tools/technologies you'll need to become semi-competent in only one stack, it won't seem like such a massive shift anymore.
I think competition is not that fierce -- honestly speaking as I can -- but that's for corporate jobs, etc.
And you _have_ to be competent or good or really good if you're older.
Else, you're just going to sound...like you sound -- old and washed up.
Not saying you are, or I am, but once you're 25+, if you bring the 'Get off my lawn' vibe, your 27-yo manager-to-be is gonna smell it a mile away, and he's gonna be feeling awkward enough already.
So I think you can be fine, but you gotta actually know what you're doing, and you have to get/be modern.