There is nothing wrong in "the old way" if "it works for me". Issues can probably start in a team but even then, old tools can rock. I remember when people introduced poetry in our dev team in an absurdly complicated way (wasn't poetrys fault but the all-wrong non-portable way of pinning decency versions). Sometimes, simpler is better.
Sometimes new tools make it simpler not harder. uv is such a candidate in my feeling and I think that's a major reason why it took off.