It's not surprising this happens actually, when as a F1 team principal, your goal and job security is tied to scoring points at this year's season, not setting up a multi-year plan to update your IT infrastructure and processes, because if you don't score enough points, you might not be around next year to see your grand plan bear fruit. And if you're like Williams, failing, underfunded and replace your TP every year, who's only there as a scapegoat, no wonder nothing ever improves.
It basically the trap of perverse incentives and very low job security. F1 shareholders won't care that you replaced Excel with an efficient ERP system, If you don't score any points on the track, you're out.
Anyway, they're not alone. People would be surprised how many well respected and profitable companies still run like this.
But F1 is special here. Adrian Newey, the genius race car designer and head of aerodynamics at Red Bull only uses a drafting board for design, never CAD, or any computers actually, to the point his secretary prints his emails and CAE simulations for him on paper[1] and works on those, to the point he is surrounded by mountains of paper. The tech community would be livid to see this.