How long to get to serious distances and elevation gain?

Got hooked on local trail running as I’m Carmel/Big Sur area and it’s so addicting!

This is of course great and I’m having a blast but I’m curious how long it takes to build a base and get to 50k distances?

I’m averaging about 20-25 a week with about 4-6k of elevation gain after taking it more seriously just under 2 months ago.

Historically I’m pretty active and it decent shape but mostly from cycling.

I’m 53 and had torn meniscus and partial acl tear last year with surgery in April of 2023.

Have a family to it’s tough to get out more than 4x a week for hours at a time. Plus, I have no interest in re-injuring myself but I’m in awe of some of the distances I’m seeing on here - really inspiring but just want to know how long it took everyone to get there?

I’m guessing years?

Anyway, I’m so grateful for this group and keep up all the cool photos, links and posts!

Edit: 20-25 miles per week.