There are way more possibilities. And the main one is that any negative effect would only be visible in a long time (let's say 10 years) and by that time it may take 10-20 years again to change course.
For instance say you lower standards for building bridges, how do you assess the success? First you may notice nothing, because all bridges under construction stay with their design, so consequence 0. After a few years, construction costs may go down because the new standard allow to cut some corners. Great! Success! Now 30 years in the future maybe suddenly the bridge has a failure that costs 20x the savings at the time of construction. Well suddenly not great. But changing the standard at that point would not fix all the bridges built over those 30 years.
Evaluating public policies is often very hard and it's sometimes only possible a long time after. I would also say that weather or not a policy is good or has positive impact has little impact on winning or losing elections. Lots of terrible policies can win you voters. Just like building the best product is not the easiest way to make money. For both goods and elections, playing on emotions works a lot better.
The timeline for some things is way longer than 10-20 years and, in cases like data collection, we simply lose out forever.
What we're seeing right now, and it's not just the US, are policies that risk depriving future generations of data that may be critical to solving problems 50 or 100 years from now. If you say that collecting water quality data is a waste of money because we don't have problems with water quality, that's a permanent decision that can't be reversed and will adversely affect future researchers. It's incredibly frustrating.
In the bridge example above, even with bridges failing after 30 years, the average person won't be able to assess whether or not it was a success or a failure. You'd have to know the cost of initial construction, lifetime maintenance costs, replacement cost, the value gained from short term savings, etc.. Coming up with a calculation to categorize it as a success or failure could be difficult if everyone is acting in good faith. Throw in politics, partisan interests, propaganda, etc. and it seems almost impossible.
No matter what side people fall on politically, everyone should consider unbiased, non-partisan data collection a vital government service. If you disagree on how the data should be collected, do it both ways and debate the merits as long as you want. Just make sure the data stays available.
We have examples of this kind of thing happening[1]; in the 1970s Eli Ron invented a new way of making concrete ceilings called Pal-Kal; it was easier, faster and cheaper. Also prone to be weak if done without care and sometimes extremely dangerous. Used a lot around Israel there were some non-fatal failures and a committee setup to investigate it banned it in 1996[2]. In 2001 the Versailles Hall in Jerusalem collapsed killing 23 people. Eli Ron was given four years in prison for manslaughter. There were no good records of every building built with Pal-Kal in Jerusalem to go and check them; now any that are known to use it can be structurally checked every year, and demolished if found unsafe because there isn't a good cheap way to strengthen them, but there may be more of them unknowingly using it.
Another is the Morandi Bridge collapse in Italy in 2018[3], it had been designed as a steel cable suspension bridge with the cables encased in concrete meaning there was no good way to check if they were rusting. The engineer who designed it (click his name in Wikipedia) was calling attention to risks and problems in his design since the 1970s without the responsible companies/government departments taking it seriously enough.
Also see how big Wikipedia's "List of bridge failures" is[4]
For instance say you lower standards for building bridges, how do you assess the success? First you may notice nothing, because all bridges under construction stay with their design, so consequence 0. After a few years, construction costs may go down because the new standard allow to cut some corners. Great! Success! Now 30 years in the future maybe suddenly the bridge has a failure that costs 20x the savings at the time of construction. Well suddenly not great. But changing the standard at that point would not fix all the bridges built over those 30 years.
Evaluating public policies is often very hard and it's sometimes only possible a long time after. I would also say that weather or not a policy is good or has positive impact has little impact on winning or losing elections. Lots of terrible policies can win you voters. Just like building the best product is not the easiest way to make money. For both goods and elections, playing on emotions works a lot better.