Did you just plant these those year or last ? I feel like they look fairly new and just need some time to settle in and start to show off. The azalea won't bloom more than 2/3 weeks in spring and then that's it. So I'd replace that . That yellow plant is pretty and looks like a nice anchor. Maybe add a yellow knock out to replace your azalea ? They have a light fragrance and are very pretty. Knock outs will get pretty big , something to keep in mind. Mine in pa got to 5 ft but I don't prune .
I had that butterfly bush once and it didn't thrive for me. Just a side note in case yours does the same. Pink delight and black knight did spectacular for me. And are common in nurseries.
Another thing you could do if u want to give your shrubs a chance before replacing them , is fill in the bed with annuals. They will perk it all up. Snapdragons and petunias are some favorites for sun !
I love your stone edging ! Looks like a very pretty bed'!

I agree with Lilyfinch! I also want to say the Knockout can get enormous unless you keep it pruned. I have the original redraz and it gets at least 8 feet tall and then I cut it way down every couple of years so it might soon outgrow the spot you have it in. Now if you cut it down every year then it will be OK I think. I don't think the yellow knockout gets that big.
Joann