I watched a game awhile back. Quality was similar to international level with Canada, US. But that's not saying much.
Difference with golf is that the women golfers are very good. 99% of us can't even dream to be that good and if you think you are, you are delusional or you are lower tier professional player.
Women's tennis is good to watch. They are competitive and the points go longer. More strategy. Plus they have awesome legs!
Actually, I don't think it has anything to do with the quality of the athletes. It has more to do with the nature of the sport. Golf is a skill more than an athletic display. Being athletic helps a golfer be better but an observer doesn't actually see it. They see a ball flying through the air and where it lands. Does a 250 yard drive by a woman look any different on TV than a 330 yard drive by a male. Same with the seniors. I will say that the women are very skilled, accurate and have the same finesse.
But when you watch women play hockey compared to men you can see the obvious differences. The women skate slower, don't shoot as hard, have less maneuverability and agility. So watching women's hockey is not as entertaining. Nobody would be interested in watching senior men's hockey either.
TBH, I think this same dynamic holds for tennis as well. I know that there are a lot fans of women's tennis, but IMO I can barely watch it because of the extreme difference in the physicality between the men and women. The men are stronger, hit so much harder, are so much quicker (foot speed and reflexes), cover the court so much better, from baseline to net and side to side, they get to balls no women could ever dream of. It's the same to me as the differences in hockey. The one big thing that women's tennis has is the sex appeal, as you accurately but probably massively underemphasized, pointed out and women's hockey does not have that.
This was further displayed when senior's golf was initially successful, they started a senior men's tennis tour, trying to cash in on the nostalgia, it soon flopped. Watching 50 year olds McEnroe vs. Borg got boring really quick and it crashed in no time. That's because the inferior physicality was on full display and we won't watch that.
So I think that golf is in a very unique position when it comes to all other sports, where inferior athleticism is still very watchable.