Having finally farmed the standard set of ships and invested tons of gear into pilots for a share in the far-too-small pool of crystals, I have to agree that there just aren't enough ships, enough ways to acquire ships, and things to do with ships. Of course RNG also matters in squad arena, but there's at least a few teams that do pretty well there and people simply enjoy different characters and factions, so it's rare to be forced into a mirror match. You can choose to fight a squad that your team is likely to do well against because of who your team is, so the RNG isn't as likely to be the entire decision factor. And I fully disagree with the statement that any fleet can win on offense.
It really pains me to say this because I'm not looking forward to so many more long farms (and other people finding the new killer combos before I do), but the only way to fix the frustrating random outcomes of mirror matches is to add enough decent ships to build multiple competitive squads, and enough viable capital ships to lead them.
And there's the fact that so many teams have use outside Squad arena; we have events specific to Sith, Rebel, Resistance, First Order, Ewok, etc. Much more fun to be had. In ships, the only thing to do is Arena, and you have to do it because it's the only way to get the currency that gives you more ships so you can place higher so you can earn crystals so you can boost the characters you actually care about.
All that said, I actually do enjoy ships, including the reinforcements concept. I haven't been successful long enough to be bored of it, but I understand where you all are coming from. I also wouldn't mind if some of the existing ships were toned down a bit so the new ones don't have to be ridiculously OP to overtake them, but that's a whole other conversation.