Question about tennis players

How can they afford to travel all over the world all year round, country to country, state to state in the US, week to week? When they have to pay their coach and trainers and anyone else involved in booking their slots into each tourney? I ask because when they dont make it to a QF, SF, or Final and or win tournaments... they dont earn much yeah? Or do they win a good sum for each round they win?

Airplanes, hotels, and food are not cheap

I believe they earn some points and money for advancing into next rounds, the deeper the run the bigger the prize pool. 

I remember Sumit Nagal brought up this topic last year as he described how tough is it for players outside top 100 to maintain financial budget to compete at different tournaments in different countries. If you are not famous yet, it's more likely you have to deal with your own financial problems. If you get some attention from media, probably you can survive with some advertising contracts or sponsored by some low-tier sport companies. Usually they will gather points and money in ITF Tournaments but again it's always tough if you are not strong in financial. 

It is the same in most sports + the movie and music industry etc. - most people don’t make shit or even take on debt - but if you succeed and join the 1%’s you earn a shit ton !

I know from Clara Tauson and Holger Rune they basically both went from families selling their houses to fund them and Tauson even had to play without a coach for 6 months to both of them now earning millions of dollars each year - and they aren’t even THAT great - Tennis as a profession is just a lottery ticket