I come in peace: why do we want a finite money supply?

Genuine question as someone who is a bitcoin noob and has studied economics at uni.

• If the money supply was finite, assuming the velocity of money flows remains stable, nominal GDP should also remain stable. This is generally accepted by lots of high-level economic models/theories like monetarism (MV=PT etc.)
• If the number of transactions made in an economy increases (e.g. due to technological change or population growth), there are two outcomes with a finite supply: (1) people spend less frequently, which won't happen in practice, or (2) the price level falls and we have deflation.

Here's my issue: this kind of deflation is generally considered a bad thing by economists, for two main reasons:

1. It requires nominal wage cuts, which literature shows are really hard to implement (consumers don't want to be told their wage is 'falling' even if it isn't in real terms).
2. Partly as a result of (1), people delay spending in anticipation of further price falls and we get a nasty deflationary spiral (e.g. Japan).

My question is what, if anything, am I missing here? Again, I'm genuinely interested and come here in peace.

EDIT: thanks everyone for the responses. Some things I still can't agree with, others make a lot of sense and have changed my views.

One thing I should have said here is what makes this kind of deflation so bad. With inflation, theoretically a central bank can raise interest rates to discourage lending and cool the economy. With deflation, theoretically they can just do the opposite. The issue here is that if economic agents expect further deflation and expected inflation is negative, it means the lowest real interest rates can go is zero (the 'zero lower bound'). This means we could have a world where central banks simply can't reach the rates required to prevent the spiral, and are just pushing on a string.

Another thing I should have said is that obviously, there are lots of occasions where deflation reflects something good. E.g. we find a cheaper way of making something, or international trade releases mutual gains. The kind of deflation I'm describing is worrying because unless we take nominal wage cuts - which is hard - businesses simply can't stay profitable.