I think Brexit has helped EU tremendously unfortunately.
I very specifically think this because UK has always been very close to USA on military issues.
Had UK been in the EU, I bet USA wouldn't have bullied UK so much, but used them to create division in the EU regarding creating our own independence from American military. For instance wat4ered down or even prevented the SAFE program, which incidentally UK isn't a member of, but Canada and Japan are!
As it is now, UK and EU are building stronger ties on military cooperation, but with UK inside EU, I seriously doubt that would have been the case.
UK is now realizing that EU probably is the better ally compared to USA. Just as other countries have been forced to, like Ukraine, Canada, Japan, and of course Denmark, that despite being a member of EU, considered USA our most significant ally for security.
That mindset has changed across EU, both because of Brexit and because of the election of Trump 2 times.
As an EU member, our closest ally is EU not USA.
UK is of course still a crucial part of Europe, and they were part of creating the coalition of the willing to help Ukraine. So we have proven that UK and EU can work together when it counts. But I think UK standing on their own, now realize the importance of EU more than they did before.
The necessary reforms to invite more countries into EU and to avoid the problems Hungary caused, will possibly also be way easier without UK, because they will probably require for member states to give om a little bit of sovereignty, something UK is completely allergic towards.
Finally the plan is to increase EU budgets, something many countries are against, but will probably happen just to a slightly lesser degree than the budget currently on the table. This too is something UK would probably also be against, and that's literally the definition of slowing EU down.