I played pool competitively when I was younger.
at my peak I was a better player than your average man down the pub, but against my male peers competitively it remained unequal.
as a woman I was nearly always smaller than any males I played against, in pool that meant I had to stretch further/was more unstable taking the shot if it required reaching across the table.
my arm span was shorter, generally meaning less power when breaking or taking long shots/ doubles.
Boobs. Boobs were a particular issue for me. Men with big bellies can kind of brace them against the table, boobs hang down onto the table. I often had to contort myself to prevent my chest from hitting a pool ball which would be a foul.
sexism/sexual assault. Lost count of the times I had lewd comments made whilst bending over to take a shot (obviously not in competitions) Or my arse felt. A common one was also a pool cue shoved between my legs when I was bent down.
As a woman I didn't feel I could go and practise for hours on my own down the pool hall like the men could, practising shots over and over again like they did. If I went I went with others, because I got hassled if I didn't. And because I went with others that meant sharing a table, taking turns, being a good sport, not being 'selfish'.
As you get older it's less socially acceptable for women to leave the kids for the evening to go down the pub for pool matches, or pool practice. The men don't really want you there either much in the same way a man turning up to an otherwise female only group would change the dynamic.
Because hardly any other women play you have a much smaller 'pool' of players to compete against who have the same disadvantages as you.