They are very slow and you will need 1000 users which makes no sense.

We have very active users (triathletes) who often train multiple times per day and can't grow our Strava user base at this point because Strava does not grant a rate increase. We need two requests per workout (get activity and get streams of activity) and only use webhooks. Every mail we receive is like "optimize your usage, check out webhooks" - that's  really unhelpful.

We also send workouts, but if Strava is not interested in those anymore, users may have to look elsewhere?

I've made a suggestion that would allow a reduction in usage (send start_time for workout in webhook) but has not happened yet.

Strava will likely soon be forced to send workouts to third party platforms (upcoming EU Data Act) so it would be smart to just do it now and not only when being forced - would be a better look for Strava.

I'd be happy to pay a fair price for the API usage.

What is puzzling is that I've checked two other accounts I have access to, and the rate limit is set to 600/30k requests on both. So technically you could create a new account and switch users to it and you'll have more requests available.

For now I'm leveraging scraping method to get around the restrictions, and a lot of hacks in the app to limit the numbers of requests, but it's far from ideal.

We have resorted to implementing direct API connections with Garmin Connect and Wahoo to get new activities,  which has helped tremendously. But sooner or later we'll run into the same issues again, especially since, as @Jan89 pointed out, you need to do at least one API call to Strava to get the start time of the activity.

You seem to know what you are talking about. I can’t get support to reply in 24 hours. When I try to comment I get a message “rate limit exceeded” And it won’t post my comment. I can still upload activities, photos and videos though. 

What I've done to get over the limits was implementing scraping - I just scrape data from their website (there are all the informations I need) for some calls, it's far from ideal but for now it works. I've submitted my app for the review with the new developer program so I hope at some point they'll increase the limits.

The thing is that scraping is much harder on Strava servers and I think it's forbidden by TOS.
Making more API calls available is totally in Strava's own interest. And again, they will likely be forced (at least for EU users) to allow it by the EU Data Act (position already adopted by the parliament and the council).

¯_(ツ)_/¯

I wouldn't have to use it (I use it rarely, as a last resort) if they'd properly review my app and increase the limits slightly. With 500+ users 1000 calls per day is nothing. They could also include more data in the webhook, at least activity type, for me that would allow to cut api calls by half. Now I need to pull data for all the activities even if I care only in some of them (rides).