Inflation reduces the value of money at the bank: the money saved as well as the money borrowed.

In an ideal world, wages are indexed on inflation (way of calculating inflation in this context can be discussed), and inflation is kept above present targets levels (central banks try to keep it at 2% these days).

That makes your debts easier to reimburse, and limits returns on savings. Have you ever noticed that people who keep talking about the "value of work" actually push for low wages and no or low taxes on capital gains, so actually wants the capital to make more money than work?

A low inflation allows big money to hoard more and more. Higher inflation means money that's not actively contributing to the economy will lose its value over time, and that's exactly what you, at the bottom of the ladder, want (and considering top of the ladder is hundreds of billions of $, ever 6 figures employees are bottom of the ladder).

Too high inflation leads to an uncontrolled spiral. Deflation is also very bad (no investment will ever happen if your money just appreciate by doing nothing). But the 2% target is not to protect you. It's made for money to make more money.

But about the link between wages and inflation: what we have today is a situation where we let cost of life dramatically outpace wage growth. So where did the inflation come from? Profits! That needs to be rebalanced.

From 1945 to the early 80's (before the €), France and some other countries minmum wages were indexed on inflation. If doing so would instantly crash an economy, we would have noticed...

A small amount is good. Deflation makes it so not spending money is more beneficial. The longer you wait to spend the more the money is worth. This causes fewer products and services to be purchased, which pays for wages. Inflation makes the opposite true. The longer you wait to spend your money the less it's worth. It encourages spending, not saving. Inflation that outstrips increases to pay is obviously very bad though.