You are making a product to sell worldwide
For devs in the east, I feel this isn't the case way more often than it is. Even though a lot of games do make it out of Japan, I don't think the mindset of the devs is "I'm making this game to sell worldwide." It's "I'm making a game for my fellow Japanese."
those non-Japanese markets are a huge part of what makes it so lucrative (I'm going to go ahead and assume domestic sales far outpace Japanese ones as well). Most competitive interactions in this day and age are online p2p, and how well you engage and keep people playing that game so that you can later sell them additional content/revisions is by ensuring that experience is good and something they want to keep playing, yes?
I honestly would imagine most of the money comes from people that have an interest in the games but don't take them that seriously. People that like to "experience the story" and other nonsense don't need amazing or even good gameplay, as long as it's serviceable. DLC is best sold immediately after the game comes out, so keeping people hooked for long isn't actually the goal, just keep them hooked long enough. Online being trash is unfortunate, but a good single experience is really all you need for the casuals, the money.
So what do devs generally do? Extensive local testing in Japanese arcades (fair enough, logistically/financially their best option), early single-region arcade releases, and test online in closed, Japanese environments. There is a considerable disconnect here. Of course there are a bunch of assumptions here and it's hard to argue how much and what kind of testing they definitively do, but much of it appears ineffectual and I have a feeling these are the reasons. An online beta is a great first step, and TBH ultimately beneficial for character balance as well.
So yea, I don't think the Japanese see arcade releases as local testing. It always feels like their bread and butter, while console releases are dessert. With that in mind, I don't think the death of arcades is going to be all rainbows and sunshine for fighting games. Sony happens to be paying for SFV, but will they want to shell out for Marvel 4 or SF6, or any other franchises. Is ArcSys going to still release things with no arcades? Tecmo seems to see money in home releases, but what about Namco? Gonna get a T8 or TT3 without arcades?
But I agree that the arcade scene is for the birds, but that's mainly because it's always holding up releases. If it weren't doing that, I wouldn't really care about it. And despite it screwing me over, I still don't wish it gone at the moment. So actually, I should say that I agree that there are better ways that devs could be making fighting games, as we've seen from western devs, but I don't think eastern devs would be quick on the uptake even if they were forced, like if* arcades died. As much as I hate getting games late, it would suck even more not getting them at all.
*when
