Switzerland's comparative advantage as an innovation hub was due to it's permissive capital structures and historic openness to white collar immigration.
All that a rule like this does is incentivize moving jobs out of Switzerland. Heck, look at UBS axing 3,000 jobs across all functions in CH and shifting them to India [0] last Wednesday.
If UBS, Novartis, Google Geneva (edit: doh, Zurich - my coffee hasn't kicked in), etc cannot continue to attract employees they will leave, and given the extremely friendly FTAs and BITs Switzerland [1] has signed either unilaterally or part of the EFTA, it's extremely easy.
Heck, look at how Syngenta went from being a Swiss major that employed thousands in Switzerland to a Chinese major that is about to IPO in Hong Kong [2] in just a decade.
Already 1 out of every 3 Swiss businesses is planning to shift out of Switzerland (primarily to the EU and US, but Asia comes up as well) [3].
Switzerland doesn't have the same comparative advantage in finance 40 years ago (why Basel when I can go to London, Frankfurt, or Amsterdam) nor manufacturing (why CH and not DE or CN) and this kind of ruling puts it's entire life sciences industry - the last industry within which CH remains a global leader - in jeopardy.
Additionally, Switzerland is not in the EU and is dependent on the EU-Switzerland FTA. If this were to pass, it would violate that FTA with Switzerland's largest trading partner. The EU can severely push back against CH, and France+Germany+Italy would very much support such retaliation as it would help incentivize Swiss businesses to shift out of Switzerland.
[0] - https://www.reuters.com/business/finance/ubs-plans-hire-3000...
[1] - https://www.seco.admin.ch/seco/en/home/Aussenwirtschaftspoli...
[2] - https://www.reuters.com/world/china/syngenta-targets-up-10-b...
[3] - https://www.thelocal.ch/20251023/swiss-companies-set-to-relo...