Whether their strategy was successful or not depends on the definition of success, but -- more importantly -- I think it is still too early to tell.
Much will depend on the endgame: if there is a vaccine soon, Sweden's strategy will look foolish, since it would have been better to enforce stricter measures and wait for the vaccine. If the vaccine takes a long time to arrive, they may have immunised a larger portion of the population much quicker than those with stricter measures (basically their Nordic neighbours) and will be in a position to return to "normal" much quicker.
Sweden has a high death-toll at the moment, but I think their strategy was a valid choice. It seems that there are strong diminishing to the measures. That is, even fairly light measures slow down the spread a lot, and the stricter measures have very little punch, but much economic impact.
Running the numbers on this, my team and I guesstimated that measures representing a 5% economic slowdown already reduce the infection rate by 60%, whilst a 10% economic slowdown would buy a infection rate reduction of around 70%. A 15% slowdown would buy an infection rate reduction of around 75%. So the thing is, the trade-off is not constant between economic impacts and the reduction in the infection rate, the policies seem to have (strong!) decreasing returns.
Sweden is closer to herd immunity than its neighbours. If the vaccine comes soon, the strategy of their neighbours will look better. If the vaccine takes a long time, Sweden's strategy may turn out to have been the better strategy. It is, quite simply, too early to say at this point.
That's a very interesting approach -- I really enjoyed reading your transcript, and your implementation of the system as a circuit is really quite unique!
I think you're onto something with your motivation: most epidemiological models basically consider the infection/mortality/recovery rate to be fixed, or at most modifiable over many years by national investments in health. It seems that, before COVID-19, nobody had really thought that the trajectory of an ongoing pandemic could be changed, so I haven't seen any models which incorporate that.
But I think it's unfair to use scare-quotes around "models". The truth is, there is a tremendous amount of insight to be gained from those "models" (SIS, SIR, SEIR, etc.). I mean, your own proposed model is even just a small variation of one of the classical models, and you don't even show that it makes better long-term predictions, which is what you criticise in the other models.
Sorry, that was a long-winded way of basically saying: Great work, but don't discount the classic models entirely!