It’s not a total ban of VPNs, I went to read a bit on the subject (easier since I’m french), it’s just that some politicians came up with a few amendments relative to the bill called “SREN” which very literally translates to “Securing and regulating the digital space”. As you may guess that bill also ticks the “child porn” box as a reason why it came to existence.
One amendment proposes to ban mobile VPNs that do no comply with European or french regulations in the context of app stores. So it’s only on mobile, nothing about desktops.
Of course it’s inapplicable in practice.
Several amendements already failed due to backlash, one was about preventing people from posting on social networks if they use a VPN.