OH is (was) the only child of physically incapacitated parents, at the time in their 80s.

Again with the caveat that this is only what we faced, you might find an entirely different attitude and process in your community and canton:

When we first broached the idea of bringing the ILs here we were told that they could not be considered dependent on us because both were still alive, and thus one theoretically could care for the other.

That their health did not allow this would not be taken into consideration. We were told that we must wait until one had died, leaving the other completely alone with no other living relatives anywhere in the world.

If any family members existed, in any country, the argument that the parent is dependent on us failed. MIL's sister was still alive, again negating our argument, despite the fact that she too was elderly and physically incapable of providing care.

It was not a question of who could best care for the parents, that was not Switzerland's (or more accurately this village's) concern. The overriding concern was to limit immigration of 'non contributors'.

But again... You might well find that your community takes more compassionate view than mine did. I do know of one person who was able to bring both elderly parents, despite having many siblings living in the home country, despite the parents needing the standard community nursing home subsidy, despite that the sponsoring Swiss resident was unemployed at the time. (Although he had a good employment record prior to this, and found another job later.) Exactly the opposite of my experience, so go figure. But I know of more people who were denied, so again, you cannot assume that one situation will shed light on yours.

I certainly understand the difficulties. We could not bring the ILs here, yet OH needed to keep working to finance their care back home. We could not abandon our responsibilities here and move back to the US to take up our responsibilities there. Lose-lose as you say.

We just bit the bullet, set things up as best we could and raided our retirement nest egg in order to fly back and forth every few weeks for several years. Ya do whatcha gotta do, it's the cost of living far away when duty calls.

After MIL went into hospice we started the process again, this time to try to bring FIL here 'when needed'. We felt we received a less negative reception this time, as circumstances had changed. But we will never know the outcome, FIL died during the process and we withdrew the application.

In our village a consideration that seemed to loom large was 'How will Switzerland benefit from allowing this application?' You might think this through as you start the process... What do you contribute to your community, financially and otherwise, that would be lost if you were forced to leave?

But again, not to sound like a broken record... Your community might take an altogether different view, you might have a much easier road than we did... as seen by my acquaintance who was able to being both parents here on purely compassionate grounds.

I know the struggle you face all too well, and sincerely wish you and your parents all the best.