Toei could have given it to Viz in the early-mid '90s and they would've done it properly (would be like their Ranma 1/2 dub), but they didn't. Instead, nepotism won, and the unproven startup with a producer who has no respect for the source material (Barry Watson) got the license. Toei had a lot of potential choices of licensors to get Dragon Ball, and they chose probably the worst one in the lineup (yes, even 4Kids. People rightfully like Funimation as they are now, but in 1994-2005, 4Kids would have done a way better version that actually begun with the original series, and the default version of DBZ wouldn't be a shitty, cropped, DNR'd version).
Funimation could have done it properly with Pioneer in the mid-late '90s alongside their TV dub, and they didn't. (Despite saying they would)
They could have done this as their one and only dub from 1999 onwards, and they didn't. (In fact, their dubbing got significantly worse in 1999,
as we all know)
They could have done this for their redubs in 2005-2008, and they didn't. (In fact, once again, the 2005-2008 redubs were
another downgrade...)
They could have at least done it for the Z era with Kai in 2009-2014 and Super following that, but they haven't; they follow the gist of the original and are a huge improvement over the 1996-2008 era, but they still embellish it in all the same ways they used to before, just to a lesser extent, they're still using actors who were miscast in 1999 but stick around out of tradition (granted, the actors clearly care a lot, so even someone as badly miscast as Linda Young when she was playing Freeza in early Kai and the video games around then was putting in a good effort, but we all know how well it turned out when the role was recast to Chris Ayres), using naming conventions and dialogue that sound like they're straight out of 4Kids' playbook.
At this point, they're not going to change their minds; Barry Watson's influence is too ingrained to ever go away.
Basically, there has been ample opportunity for this to happen in the past 25+ years, but neither Toei nor Funimation have ever cared about doing this right, and the efforts that did do it right (Pioneer's movies, Westwood/Ocean/Blue Water's GT, allegedly Ocean's Kai to an extent at least a little greater than Funi's work on Kai) have been brushed under the rug by Funimation in their effort to be the only dub cast anyone knows about, and unfortunately, despite their eagerness to be the only Dragon Ball dub, they have no willingness to do a truly faithful dub. Their work right now has been in a pretty steady groove since about 2007, and it's successful, so no one on either the business or talent side wants to shake things up now in 2021. We're way, way, WAY past the point of no return.
So, even though it's entirely possible to do, there's no interest from the people who would need to be interested, and there simply never was any interest. The people who work at Funimation now most likely would have chosen to do it faithfully if it was a new acquisition (just look at their work on My Hero Academia and One Piece), but it's too late to make that choice now; it's generally considered more important to keep it similar to how it's always been. Same goes for the home video situation; the people at Funimation like the shitty DNR'd look, and it's sold well (since we've never been given an alternative), so we're never going to escape it. But at least as far as dubbing goes, there's always the subtitled version.
The point of Dragon Ball is to enjoy it. Never lose sight of that.