I got over the shower thing the first time I used one at my last place of work. A dank, wet cubical festooned with a load of others musty towels that'd looked like they've never been home to be washed, no thanks. A shower at home just before leaving and some wet wipes & a can of deodorant if feeling particularly grotty.
Some way of drying kit is a must though, I'm lucky that I have an old drawing board behind me and a radiator to hang stuff on when it's been a wet ride in.
I'm not at work today, but this is kind of my day job. I've just messaged you.
In decreasing order of importance to encourage more people to cycle to work:
Secure cycle storage with sheffield stands that can accommodate a wide variety of bikes (there's a TfL document on what good storage looks like and why). By secure, I mean hard for people who don't work there to get into, ideally well lit and dry. That storage placed close to the entrance to the office so people can actually find it and don't have to wander round in the dark to get to/from it. It's always nice to have a "lock rail" to discourage people from leaving their d-lock on the racks.
I wouldn't worry about charging infrastructure. Most offices come equipped with lots of sockets, and the average commute is unlikely to flatten an e-bike battery.
Safe routes from the entrance to the cycle storage.
Changing and storage space. Somewhere for people to safely put their riding gear to dry during the day and know it's going to be there when they come back. Enough of it that you don't worry about there being space for them when they arrive. Good drying facilities are nice, but can be expensive. Showers are also good, but can be pin to get installed.
Good signage that tells people where the facilities are. You'd be amazed how many people don't knwo what facilities they actually have at work. And, seeing signs to the storage encourages people to try it for the first time.
Route maps for how to get to your site from a variety of common places. Not knowing how to get to work safely by bike is a big obstacle for people.
Pool cycles are a nice to have but they can be very expensive, a pain to look after and poorly used.
Those are my initial recommendations
Good point on the cubicle thing. Changing after drying in a wet humid cubicle is rubbish. Always worried someone may come in when changing in the communal areas as it's unisex.
Also never enough hooks. skanky towels occupying each one.
Best thing i did was to buy a motorbike.