My current rule of thumb is - 8 to 10 weeks in a startup - 6 to 8 months in FAANG
Assumptions - Internet/App based consumer product - End to end feature & not product improvements
Surely the scope of work is going to vary massively that is would make it really hard to answer your question accurately.
Do you have an example of what you consider a feature and how long it has taken you?
In my case, I work in online mapping, and developing a feature which allows people to convert between projected coordinate systems when they download data took about 5 days to complete and sat in dev and uat whilst the entire project was being worked on.
Solo, I've built a logistic management & tracking system in a day, from scratch. It was ugly and unstable, but never dropped the ball. I only worked that fast because we had more customers than was manageable manually. Never replicated that feat.
As a team of 5, the most ambitious was a chat feature done in 2 months. Built on a paid platform, of course, but a lot of it had to be custom integrated, like UI, offline storage, and multiple users managing a company account.
Last night one of my customers mentioned they wanted something new on the site. I'm pushing it live tonight.
Truly it's dependent on what you mean by features, project complexity, team, etc.
The proverbial length of a piece of string.