On the topic of progress in science I personally believe that fields where computation is useful/important (such as biology, chemistry, etc) will continue to progress without much issue, as computation for now at least is continuing to grow without much issue itself, and as it grows it will take at least some time for the appropriate computational methods to be developed. However for other fields where computational resources may not have as much significance (such as theoretical particle physics) I can see that stagnation may be an issue.

As many other commentators have noted there are lots of problems in academia to do with funding and how ideas are spread, etc, however these problems seem to be fundamentally economic or political in nature, so just throwing more bodies/scientists at the problem will not resolve them, therefore there must be systematic change from the economic/political sides to improve the situation.

Another thing that pops into mind is in regards to low hanging fruit. An obvious solution to why progress may be waning in fields where computation is not important is that all the easy work has already been done (see Dirac's quote about 2nd rate physicists doing 1st rate work in the late 1920s with QM) and thus in order for there to be progress

1) students must have significantly more background knowledge as they need to know more about what does or doesn't work

2) creative ideas should not be shunned

1) imo is already a bit of a problem and I guess at one point in the future there may be issues once humans reach limits to how much their can learn in a certain time but for now this can be mitigated by being more efficient in how students are taught. For example in my own personal experience in math once you get to PhD/research level topics nobody reads textbooks to gain broad knowledge on a topic but rather reads them for reference. There's just too much to learn and know so instead if you're researching some topic you try learn whatever you need as you go rather than from a bottom up approach.

2) is linked to the problems in academia as I mentioned but I guess as more technologically advanced societies should have the advantage over less technologically advanced ones and science is of course basically a prerequisite for technology advances then this problem will solve itself natural selection style.

One other thing I would like to note about academia with regards to inefficiencies is how much is still locked away behind paywalls or other inefficiencies due to decentralization. For example lots of historical journals I've seen that only have the content in a certain language, etc things like that. For the scientist and for anyone in general interested in science it would be easier if there was just a central place to look for topics that would include all historical content in some common language so it would be easily accessible. An example again from math is me having information in a Hungarian journal that no longer exists. Not only is the information behind a paywall but also it was in Hungarian and only photo scans so I had to OCR it myself. This is an example of an inefficiency and I doubt most would go as far as I did to find that information, so potentially you have huge quantities of information that may be lost unless it is cited by modern literature on the topic, which is not always the case.