I work for a company that for the most part[1] does not pay for business class travel at the moment.

My position has me traveling 200-300K miles a year. I, like all of my colleagues, try to minimize and avoid the travel that we do. Many of my colleagues outright refuse. This makes them less productive. One of the big reasons people avoid travel is the lack of J class at the moment - this means either arriving totally stuffed (and worse, for those with families, returning totally stuffed) or spending less time with families. Going out early/taking time off on your return is permitted and even encouraged, but it rarely makes up the difference in my experience.

I manage it with SWUs, creative bookings, mileage upgrades, etc but it is tough. I've flown across the Pacific multiple times in a month, often continuing straight on to Europe after that. I can tell you I am not in peak form and it can be a struggle. I pick the travel I take based on what I enjoy most, as well as what is most beneficial to my role and the company.

To add some interesting datapoints: I pay for personal travel in J (or at least, premium economy) - my personal time is too short to spend it in Y. My employer tends to pay above average for the role we do. We struggle to fill vacancies - there's simply a shortage of talent in my area. Like others on this thread I get calls weekly, if not daily, from recruiters trying to get me to other employers.

[1] We do permit business requests for travel over 9 hours, but only a percentage are approved - typically for medical issues, traveling with a customer, or for very senior executives. The policy has been acknowledged internally as a problem, but right now it isn't going to change.