One thing to note and that's a personal opinion is that even though the rise of the far right was a slow but steady thing since 2002. I think Macron's strategy since 2017 gave them a great assist.
Macron's started as minister in Hollande's government. Hollande was a leftist president but on the social-democrat wave. Even then, Macron was seen as a Rothchild banker and probably too right of the Socialist party he was part of.
In his 2017 campaign, he surged as a social-democrat with a centrist bias and took most of his votes from the Socialist party almost killing it in the process (they got 6% for those elections, down from 28 in the 2012 ones)
Since 2017, he's drifted rightwards and in the 2022 elections, he campaigned basically as a (moderate) conservative candidate, almost killing the Republicans this time (they got 5%, down from 20 in 2017).
By doing this, he's now successfully created a strong centrist bloc (which really is neo liberal / conservative). However, he did so by burying the historically so-called moderate left and right parties (Socialist party and Republicans).
Those moderate blocs somehow acted as balance to their more radical counterparts and historically in France, we had 4 strong blocs (far left, left, right, far right) with a relatively weak center. That allowed for ideological alliances between blocs of the same side and clearer boundaries between left and right.
Macron sucked the life of the two moderate blocs to realize a strong center but then pushed those who didnt want to compromise further ideologically. That gave LFI the huge boost it needed and RN the space it lacked to dominate the right.
We now have 3 strong blocs (left, center-right, far right) and it's a mess because there is no path to actual alliances as every bloc somehow see the other 2 as a danger to democracy.
Macronism likely died with the dissolution and hopefully the strong center idea dies with it as well.
I need the Macronist bloc to finally be the moderate right party and taking space from RN to blow its bubble. By drifting so much right the past years, it already gave room back to the Socialist party which rose from the dead those elections.
Centrists are a plague, choose a side already