I think Monaco are trying to step up because they have been active in the transfer market this summer, they already aquired both Paul Pogba and Ansu Fati and you all know how reputable Monaco are for grooming young talents to stars. I really hope Pogba and Fati will excel at Monaco.
They saw a good opportunity and seized it, signing Pogba is a sign that they're ready to step up, but it doesn't end there cause to challenge this current PSG team you'll need a squad that's almost close to what they have, we saw what PSG have done over the years, what makes them outstanding is that they invest on the best players, younger talents that would last in the team for years, take a look at Mendez, Barcola, Doue, Nevez, etc these are not just talents but the future of PSG and if Monaco or any other Ligue 1 team could replicate that maybe they'll challenge and win PSG in the near future, they're very strong but not invisible.