Macron isn't stupid he knew not to take Putin at face value.

Aside from the diplomatic front, France has the first round of its Presidential election on the 10th of April. Macron didn't announce whether he was running again or until recently.

Macron is a center right (for France) politician, but the far right in France have followed the nationalist, pro-Putin stance that other far right voices in the west have taken. Getting out ahead of that quagmire and showing himself to be leading the diplomatic effort would help him in the polls. It is worth remembering that Macron is deeply unpopular in France. Pulling attention away from domestic issues and refocusing on Ukrainian could help him skirt criticism of his various domestic policies. Boris Johnson in the UK is doing exactly the same thing (although the UK general election isn't until 2024).