Tell the people in the sports club that you don't have WhatsApp and that it's rude to force parents to do business with Facebook just for their kids to play sports.

When you cave and install WA, you make it harder for the next parent, just as all the ones before you made it harder for you.

If you want to be rid of these things, you can't get there by using them because you think you have to.

The people in the sports club will roll their eyes at you because [they think] you are a tin-foil hat wearing lunacy who is paranoid about surveillance from the boogeyman. They will refuse to switch their mode of communication that works for them and everyone else for one person (you) who is just causing trouble for no reason.

The vast majority of people don't think Facebook is the abhorrent service it is, and an even larger majority don't realize WA is owned by Facebook.

> The people in the sports club will roll their eyes at you because [they think] you are a tin-foil hat wearing lunacy who is paranoid about surveillance from the boogeyman.

That's not true. A lot of people are a lot more concerned about their privacy these days.

I reply to people on Telegram when they message me on Whatsapp if they happen to have a Telegram account.

That would make a cool bot. Followed by block them on Whatsapp. One by one no more whatsapp.