There's upwards of £600 million getting spent regenerating the city centre over the next few years. From plans I've seen, most of High Street is getting rebuilt, down to Mackie's Corner. There are apparently plans, separate to High Street/Vaux/Sheepfolds, for Holmeside and Park Lane area, not that I've seen them. The plan is basically to reverse the "doughnut effect" the city centre has gone through since the late 70s and get people living and working in the city centre again. It'll take time though for it to start to work.
Sadly, though, retail us screwed. The internet and COVID have pretty much finished off the High Street. Add in that too many retailers now want to be on our of town retail parks, where business rates and rents are much cheaper than town and city centres, so are closing and relocating high street branches.