Not sure where you are getting this 100bitcoin/day number from. In a few months we are going to be hovering around 5 bitcoin reward per block, probably. Maybe less, but let's just assume 5 (subsidy+fees). If Braiins crawls back up to 5% of network hashrate (which would be amazing considering theyre sitting at 1%ish now), that is on average 7 blocks per day. 7x5 = 35 bitcoin of reward on average per day. Now the question becomes what percent of those seeking payouts will want Lightning payouts? I think we can agree it will absolutely not be 100%.

But what if they only get up to let's say 2% of hashrate after going lightning (maybe steady climbing after that as difficulty continues to trend up), then they will get 3 blocks per day, roughly on average, that's just 15 bitcoin per day.