Well, Mercator projection is most helpful for maps used in nautical navigation:

The Mercator projection was designed for use in marine navigation because of its unique property of representing any course of constant bearing as a straight segment. Such a course, known as a rhumb (alternately called a rhumb line or loxodrome) is preferred in marine navigation because ships can sail in a constant compass direction. This reduces the difficult, error-prone course corrections that otherwise would be necessary when sailing a different course.

That being said, is a bad projection for other purposes, and it's probably better to use other projections in general education. That being said, any projection will have certain disadvantages under the right or wrong conditions.

Probably a good call to switch, though I refuse to believe it was kept so long for other reasons than "this is how it's always been"

Looks like the vote passed, with only one country voting against it (I guess everybody knows which one). However, it will be up to the member states to implement it anyway.

it's still a step in the right direction though 👍