Hello,
iam a designer with knowledge in increasing conversions/sales. I can say to you, a professional and usablity redesign like acf did, will generate a train of sales...
Rank Math has a modern style, or slider revolution and many others (just a little inspiration)
Also it needs a layout designer for the pages, where people insert data. These Tab boxes and other layout stuff is rustical and can be designed too - a small layout designer would be great .
There are some admin themes out there, take a look at adminify for styling
https://wpadminify.com/modules/admin-columns/
best regards