They don't, they already killed their Adobe Xd[0]. Even if it was still around, it was in a different league.
So they very much betting on the deal, they don't want to be out of the UI/UX space entirely.
[0] - The Silent End of Adobe XD: >>36637055
I do wonder how Adobe will fare with empowered governments in the EU, UK, and US that want to thwart these types of acquisitions for big tech. Frankly I hope they succeed too. Mergers are not good for competitive markets and Adobe nearly owning every tool out their in the design space is extremely bad.