Honesty, it would fix some of the show issues but not all of them,

Plus let's be honest, the character that most people cared about is probably still ain't going to show since Daisy would have ruined what Fury wanted in the first place.

Although I still say that it should have bene Melinda who was in that plane with Fury instead of Mason.

No. Adding characters doesn't make up for bad writing. Batman v Superman is still proving that nine years later.

Now that Coulson is an advanced droid, I see no reason why he can't come out of secrecy. He would have been fun. Also seeing Daisey with Fury would have been satisfying. Would it have made S.I. better? Not sure. But more characters allows for more story ( provided they don't die off unceremoniously like Maria Hill )

Not all but a few members like Coulson, May and Daisy would have been fun to see

I would have really liked to see Coulson, May and Daisy make a reappearance. On the other hand, no one should ever ruin FitzSimmons by putting them back in the MCU. They deserve their happy ending after all that they’ve been through.