1. Viking’s failure caused a two decade lapse in Mars exploration

No....And I am not sure what you mean by 'failure'... It found no concrete proof of life, ONE of the life experiments- the labeled release (Dr. Levin's experiment) gave a result that Levin claimed for decades was proof of life. It wasn't, the problem wasn't just that life can be more alien than we are expecting, but the conditions of the surface were more alien than expected... Viking proved nothing conclusive about life on Mars, but that hardly makes it a failure, and I don't think its failure to find life impacted the length of time it took for us to return. ANY tests on the surface are - in my opinion- unlikely to EVER find any sign of life or its remains- the surface is far too hostile - unless life progressed to the point that it could leave a fossil trace, we will NEVER find life on the surface. And since the leap from single cell to multicellular life seems to be the primary stumbling block ... Earth was stuck with single cell organisms for 2-3 billion years before we made that leap, and then things exploded from there.... It is unlikely we will find obvious fossils on mars

The surface of Mars will break down any organic molecules into component parts very rapidly. I am not hostile to the idea that Life once existed on Mars... I actually think there is a fair chance it did.... and I will go a step further - if life ever existed there, then- as mars changed- it adapted and went DEEP underground.... we find extremophiles miles below the surface on Earth- but looking on the surface for life is highly unlikely to yield a positive result.

I am not sure why you call Viking a failure.... It taught us about the surface conditions and gave a null result on life at that spot, I hardly think it was responsible for the cadence of probes sent to Mars...

Certainly, if it HAD found life, conclusive proof, then yeah, fleets of probes would have been sent- but that was unlikely in the extreme from the very beginning.

2. Budgets OBVIOUSLY have an influence over mission planning.

Well... obviously that is true- but the implications that you draw from that obvious fact are just... weird.... The monetary constraints, along with the size weight and power (SWaP) budgets mean that you have to find ways to collect the most meaningful data that you can with what you have got... If you get an instrument on a mars mission, the odds that you will get another shot are pretty damn low, there is a selection process and its very rigorous- if you cannot justify the resources you require then you are cut.

You seem to think the incremental approach is some way to game the system - to draw out the the funding... it simply isn't the case. In fact, think about Viking- If a previous mission had truly analyzed the surface conditions and had revealed the presence of super-oxidative compounds on the surface, then Levin might have had a chance to design a better experiment that would be more conclusive.

The more you understand the conditions under which you conduct an experiment, the more confident you can be in its results.

The rovers found no life, but they launched them over and over- finding signs of life would be cool, but highly unlikely even if you assume that was there once

For sure, no scientist would want to drag out their investigation of potential life in the solar system. I agree that makes no sense from their perspective. But for long term NASA budget planners who are not scientists and whose job it is to secure funding from Congress and the White HOuse, it might make sense. Try to get out of scientist mode for a minute and think about that.

See, that is where you get into la-la land... NASA has NO idea what the priorities of the next administration will be- That is why we are losing the space race against the Chinese (yes- losing it despite the recent success of Artemis II). Every 4 years priorities change more or less randomly, how can you possibly think that they can somehow attempt to game the system decades ahead of time.... ? When changes of administration also lead to changes in NASA leadership at many levels.... there is no permanent cabal that can oversee a decades long plot...

Believe me- I could write a goddamn novel on the organizational dysfunction at NASA, but the sort of thing you are suggesting implies a level of continuity and competence I _WISH_ NASA had....

I have a fascination with organizational dysfunction... Sometimes its systemic, sometimes its the result of a few toxic people- but I find it fascinating, and valuable to study... if only as a study in what NOT to do.

I remember walking into the building of a high profile organization at NASA, and walking down a hall that was covered with over 27 'motivational posters'.... the walk down that hall told me what I needed to know- it was a culture of fear led by inept bullies... Big fish in a little pond that wallowed in the power they had.....and I was right.

the most venal are also the most stupid, there is no way to game the system as you are suggesting.