Why do the champs fight so sparingly now?

You can fight every 12 weeks , if the opponents are easy beats, when you get to the very top you can fight the very best guys maybe twice a year, level of competition is what governs how active you are.

They are making huge amounts of money as well, not feasible to fight more then that. And also milking fights, until they either dont fight at all or fight when they are 70years old.

NONE. Besides Canelo and 40 year old Pacquiao, NONE OF THESE GUYS bring in any loot, let alone PPV sales. AJ earned something like 60-70 million dollars in 2018 and will be close if not in the top ten top sports earners for 2019? Fury signed an 80 million dollar ESPN deal and just netted 15 million dollars from his WWE appearance(s). I'm not sure what you define as a loot, but they seem like some pretty significant figures to me.

Not enough TV dates, too many champs. :)

Most of these guys are PPV stars and you can't really fight too often on PPV. Also, they probably have what they set out to achieve, the rest is just earning money and establishing / continuing a brand.

Reducing the wear and tear reducing the risks of losing or getting caught „in cycle“ Increasing the purses Giving a future cherry pick the time to get momentum

You fans complain about everything that’s why if they were to fight more often that means you’d have to settle for fights against fighters in the top 25. And we all know you boxing fans won’t tolerate that if a fighter isn’t popular you call them bums. Plus that was back in the old days when they were fighting for peanuts and retiring with chronic cte. Doesn’t make sense for a Hw to fight more than 4 times a year.

limited budgets and big rosters. some are just lazy

I don't think they will make more fighting 5 times instead of 2 or 3 times The less they fight the bigger the event is when they do fight

Starting from when Mike Tyson won the heavyweight championship to when he fought Michael Spinks, Tyson fought 8 times in almost exactly 19 months. In the past 19 months: AJ has fought 3 times. Fury, 5 times. Wilder: 3 times. Why don't the modern heavyweights fight nearly as much? I'd go even further to say it's a trend throughout boxing, not just the heavyweights. I'd venture to say there are fighters in every weight division that are fighting less than 3X a year, for whatever reason. Just one of those things, if I had my druthers, I'd like to see at least 4 per year, even the champs...

Starting from when Mike Tyson won the heavyweight championship to when he fought Michael Spinks, Tyson fought 8 times in almost exactly 19 months. In the past 19 months: AJ has fought 3 times. Fury, 5 times. Wilder: 3 times. Why don't the modern heavyweights fight nearly as much? - -They ain't prime Tyson...Duh!

Mainly because they make fck you money every time they get in the ring. The champions that you may thinking of in the past with a few exceptions had to fight 4-5 times or more a year to make a living.