I think it must be about 18 months ago, well actually it was once I received my London60 pass and I decided to visit every railway station in London.
Simple task. How does one access London in 2021, or any year for that matter?
Get a taxi? Take a train? Drive into London? Helicopter? Boat rides?
Walk, sounds like a great idea, or cycle, or both?
How about just wandering around London using google maps, or bing, google earth, layers of London, in your dreams?
The simple question is. What is stopping you from any of these suggestions?
These links are some useful suggestions of mine, I can definitely recommend accessable.co.uk who visit a public venue and describe in great detail the access and that place. It does not appear to cover many train stations these days, but is good for colleges, hospitals, theatres and some shops etc.
I cover many of the London rail stations to an extent, the covid thing has stopped updates quite a lot this past year, but some good research can be found for accessable stations, and obviously TFL should provide all of this, and do provide limited detail.