Is Garmin working on a version with esim?

You need to log that on ideas page.

https://www.garmin.com/en-US/forms/ideas/

Personally think it is unlikely that functionality will be more than the 945LTE version which is the current alternative for LTE connect ability. Very limited functionality though.

For you to make the choice.

Do you want good connectivity? Applewatch or wear os device is better than garmin.

Do you want a good sport device? Garmin is better than Applewatch of wear os device (except maybe the suunto 7)

Do you want a good activity tracker? Apple watch or Googles wear os with fitbit is a better choice.

Do you want a good smartwatch? Apple watch or wear os device is the way to go.

If you do want connectivity and can live with quite good, but not the best, sport functions, garmin is not the best choice.

Maybe I asked an imprecise question. Is Gramin working on models that have more developed features than 945 LTE? There is no model in the offer that really allows you to leave the phone at home. I would prefer to get this information from someone inside Garmin, not advice from users.

Also not what you want to hear: Garmin is not going to spoil their product secrets in some forum here. 

Every company has a communication strategy. By not informing users/customers about the directions of device development, the company increases uncertainty, which causes customers to flee to other manufacturers. It shouldn't be a secret if there will be a range of esim card products at some point in the future. This should actually cause users to stay with the GARMIN environment (device and software). I don't know if Garmin has channels other than its own forum to share with users what awaits them in the future.

I don't know of any manufacturer of gadget devices (whether that is sportwatches, fitness trackers or even smartphones) that shares their product roadmap in detail with their potential customers.

All big companies have special teams on their paylist who know or research customer behaviour and I can assure you they all do what they think is needed to sell the most products.

Your assumptions are wrong and your expectations are unrealistic. (he, I'm dutch. I'm allowed to be rude ;) 

Great question. I am hoping that the Forerunner 965 will have cellular connectivity. Garmin is making itself irrelevant again Apple Watch Ultra unless they start to add cell connectivity very soon