deep siren
There is always a risk for your growth if you are the smartest person around the table.
Single dev working on dozen projects is a warning flag. Your company is organizing work on a heavily suboptimal way.
If dev practices are as little mature as work organization practices, then you might be skipping lessons indeed.
Senior devs leaving and no new senior recruitment is also a warning flag.
It's great that you took ownership and delivered a high profile project. You deserve to be proud of what you achieved and be promoted.
Titles matter only a bit. A promotion shows good deliveries, but a title in a certain company can mean very different level in another company. Hiring managers know that and your skills likely will be evaluated anyway.
So the big question is are your skills growing? Are you aware of good dev practices and can use the most common tools?
Are the projects you delivered stable in production, maintainable and scalable?
There could be unknown unknowns, things that are in your blind spot. You made the project work, but you might not be able to judge if it is actually good.
Is there someone in the company or outside who could mentor you?
hidden osprey
*Also thanks for the response 😅