We dont even know if they would really be having that active responses or support team on their site or platform.
It's fair to assume that if there were any serious, constant issues i.e. with people being unable to withdraw - we would see a lot of complaints in this thread or in scam accusations topics. That's just how it works, if you feel treated unfairly (or scammed) and have no luck getting help from the site's support, you'd almost certainly go wherever you can to vent out and leave a negative review/feedback
I think it wasn't really just about people leaving. It is also about why people left, because LL decided not to run this anymore and decided to focus on his life. Which isn't a bad idea, like this is a casino after all and it's a business and if the business doesn't bring in enough money, or even if it brings in enough money, sometimes you may want to just leave.
Why would you think that site is losing its player base and/or activity exactly?
Looking at the stats from
https://dicesites.com/bitvest it looks like the number of bets is fairly stable compared to previous years:

I think the number of bets is a better metric of activity than say the daily amount of bitcoins wagered, as the latter is way more affected by bitcoin's price.