You all overreact

the flaw in your argument is that you presume everyone can get their fleets going to supply the coliseum characters. but if everyone did that, you wouldn't be getting all the rewards because it is competition based, and to beat the competition you have to pay more.  if you are newer, you can quickly outpace your competition through more payment compared to being in an older shard where others have built up more over time--if you didn't stay consistent for years, you will have fallen behind.  my guild has more experienced members than me, but i am raking in more crystals than everyone from fleet (squad fuels fleet too btw) because i face easier/newer competition.  

and just like your fleet being based on you paying more than others, the coliseum is the same.  at inception you were pitted against others in a shard and literally would become a payment war going back and forth each round vying for the next reward tier.  they recently mitigated that to a degree by capping how far you can level up... sort of... yet then they added some arbitrary aspect like your allies GP affecting your loaned units levels, so now your allies decide who gets more rewards for the most part--you can still screw up and use poor loaned squads, but you don't really see that at top levels of the paying players.

i would say the new loaned units concept makes it a little better, yet at the same time kinda dumb (ally GP based).  but those earlier complaints were completely justified.  i guess you were fortunate enough not to experience a 3hr coliseum battle of 1dmg attacks until the boss clears.  a guild member reported one that lasted 12+hrs only to alt tab and erase the battle.  and see the last era, if you didn't pay to get all your characters to 5+ stars which meant you had to pay out the max up front early on in the era, you been kinda screwed--cassian journey unavailable, so you will see those who have r10 cassian while you are stuck for months with a r4 cassian, unable to get to higher tier of the event for more rewards... because you didnt pay the max at the start of the era.