Near my workplace is by far the most convenient way for me to give. No appointments available at all for 2 months, and no appointments I can actually make it to for 4-5 months.
Near my home, I'd have to work from home for a day or have a day off, plus it's a longer journey time to the donation location. One appointment in 3 weeks that I can't make, otherwise nothing for 6 weeks.
There's also a permanent donor centre I could perhaps visit on my way home (and get home late). Unfortunately it only advertises appointments 3 months or so out, and all of the late slots for that entire time period are taken.
Overall it seems to me that for any appointment I might plausibly book, if I don't do so then someone else will always take it instead. And plenty of people must be having a similar experience, which means that if the blood service wanted to increase donations, they just need to put on more donation sessions.
I could also just turn up without an appointment which would probably be ideal for the blood service, as if someone misses a booked appointment then they can fill the gap with me. But it could mean quite a big wait, so I'm not too keen on that.
If I had one of the blood types that they're proportionately more short of, I might make more effort, though I think they should then reserve more appointments for those types. I am also ethnically South Asian which they say they want, but it's not really clear why that would be important in itself.
If I do give up I'll see if the situation seems to have changed in a few years.