Tesla has the highest profits of anyone in the industry, so from that perspective I would say they are the leader.
If you are using production/sales volume, that is true...for now. Nokia was once the leader in the phone industry. I am betting that you will not be able to make that statement in 2029 or 2030.
Hell Tesla already had the best selling vehicle in the world with the Model Y. I think the trend is starting to clearly emerge.