It's hard to define what "influential" means in this context. I kind of agree that Messi didn't do anything not seen before, he just did a lot of already existing things, better than anyone and at an incredible speed, during 10+ years.
That said, one could argue that Messi was very influential in their rivals. All their rival coaches spent Messi's career trying to figure out how to stop him and there was a lot of evolution in tactics around that, with some like Simeone and Mourinho basically building their whole tactics around the premise of stopping Messi first, then everything else.
It's hard to define what "influential" means in this context. I kind of agree that Messi didn't do anything not seen before, he just did a lot of already existing things, better than anyone and at an incredible speed, during 10+ years.
That said, one could argue that Messi was very influential in their rivals. All their rival coaches spent Messi's career trying to figure out how to stop him and there was a lot of evolution in tactics around that, with some like Simeone and Mourinho basically building their whole tactics around the premise of stopping Messi first, then everything else.