It would be very bland that's for sure. One of the main reasons why I'm so attracted to late 70's, 80's and early 90's anime art styles is that the characters have 'character'. You look at them and they stand out from everyone else. You can even see background extras and they have their own unique look and style about them. Effort went into creating those characters. That is not the case with modern anime. Not by a long shot. They almost all look like carbon copies of one another and have almost no personality to boot. They don't stand out from the rest, instead they all look like customised clones. Change their eye, hair and skin colour but the face is the same shape. The effort that went into creating characters in the past is simply not being done now. And it leaves much to be desired of the industry. Though that is not to say all companies do this. There is the odd anime I've seen that manages to interest me, but unfortunately, those works are so far and few in-between.