We have small, usable quantum computers and have grown them for years.

We have never had fusion power on a small scale (we have had fusion ignition/reaction, but never [afaik] generated usable power), let alone showed continuous growth in scale of that power over the years.

They're not the same. Fusion is a 'science' problem, quantum is (mostly) an 'engineering' problem.

Re-read my comment and then point out the spot where I advocated ceasing research and development of anything.