I am dismayed at the thought that next up is arena eventing at the Olympics but I believe it is going to happen. And just like what happened with the introduction of the short format 20 years ago, it will replace eventing as we know it at all levels of competition. What a shame. Horsemanship will be worse off if that happens. Riders will feel the need to ride recklessly in order to win, more falls will occur as a result, and horse fitness will be prioritized last/not at all. Perhaps a small group of people will band together to organize unrecognized events featuring actual cross country in an effort to preserve the spirit of eventing, and participation will slowly dwindle as time passes just like the classic series.
I was thinking, however, that I might be ok with arena eventing IF they brought back Phases A, B, and C and the 10 minute box. I know this will never happen but hear me out: IOC got rid of roads and tracks and steeplechase due to arguments of lack of space/expense. While you do need a ton of land to run A, B, C along with D, if you moved D into the arena you could have all that space for A, B, and C, and it is not expensive to rope off land for A, B, and C. If this was done perhaps horsemanship could be preserved/rejuvenated.