The data should be accurate though. Any data-driven decisions can easily miss the original intentions if they're made with bogus information.

Looking at browser usage data from GA when Firefox specifically blocks it quite often is useless.

What's your proposal? Because taking an approach that isn't data driven means it needs to be a replacement, and you need to convince people that it's worth the risk of nepotism and bias.

For starters, how about not using a proprietary service from one of the biggest tech oligopolies which has strong economic incentives to misuse any data that passes through it? If government needs accurate tracking numbers to base its decisions on, it should roll its own tracking for those numbers.

Not a great proposal, frankly.

My proposal was simply that data-driven decisions should be made based on accurate data.

Nepotism and bias aren't the alternative here. If you require that decisions are driven by data and you don't have access to accurate data, you should default to doing nothing. If anything, nepotism and bias sneak in when decisions are made despite the fact that no accurate data is avaliable.

Just use progressive enhancement instead, so the site works in all browsers.

https://en.wikipedia.org/wiki/Progressive_enhancement