It's never been a requirement for any of the car's I have owned by any of the insurance companies I have been with so no, I do not have a tracker and never had one ever.
No.
1. The tracking companies do not have a good record in finding stolen cars.
2. Some insurance companies misuse data from trackers to find excuses not to pay claims.
3. Most modern cars are online in any case and can be tracked via the car's app on a phone by owners