It's not a straightforward clear cut issue. The bit I've highlighted below is a big part of the issue. CapEx is limited to $45mil a season, so it will take Williams many many years to get their infrastructure up to par as the rest.
What the bigger teams did before the cost cap came in, was to spend like mad on infrastructure so they have a built in advantage that smaller teams will struggle to catch.
The older your facilities are, the slower and less economic the processes are. It costs you more more. Therefore something has to give. So you don't produce spare chassis's and concentrate on other areas.
It ends up being a vicious circle. Which is why I think smaller teams should be allowed to break the cost cap ceiling for CapEx so they can bring their infrastructure up to the same standard as the big boys and not have to spend 10+ years trying to do it within a cost cap.
https://www.the-race.com/formula-1/williams-f1-crash-cost-chassis-albon-sargeant/
"...
Williams ended up well behind schedule due to a combination of outdated processes and systems, limited facilities, and a big change in the composition and management of its car build.
That gave it more work to do and far more hassle with a lot of the same infrastructure restrictions, so something had to give.
Williams needed to sacrifice spare parts, performance updates, or the back-up chassis for its pre-season focus. It chose to go ahead with only two chassis, hoping it could deal with any damage on-site, with F1’s ultra-competitive midfield demanding more performance focus...."
"...Unsurprisingly the cost is enormous. The repairs, the replacement floors and wings and suspension components, at least two new gearboxes, the unexpected need to transport the chassis - it all adds up, and the three accidents are likely to cost Williams well over $2million once the full extent of Albon’s Suzuka crash is understood.
Williams is no longer in the financial grave it was in a few years ago, but F1’s a budget-capped world now. And all of these costs will come out of that allowance.
Every team does build a crash allowance into its budget cap projections for the season. But we think Williams is going to be pushing up close to that limit if not past it already. That means, more likely than not, Williams’s development budget will take a hit this season at some point.
It’s problematic given Williams is already behind the curve this year thanks to the winter problems which meant some development items that should have been there for the launch spec still aren’t on the car now. That’s partly why its car is only eight-fastest and yet to score a point this season.
The work is going to be either paused or diluted for the second time in a couple of weeks because the focus at the factory will have to be on repairs..."