Scientific incentives push to build new not build on
Although the efforts of open hardware and open science in general are great, egoistic scientific incentives imply that researchers would prefer to build new tools rather than build on tools. That may explain the proliferation of many projects targeting the same issues (see how many light-sheet microscopes are being released, none of which leverages open microscopy frameworks[@hohlbein2021aOpen microscopy in the life sciences: Quo Vadis?]).
While reproducibility is the key factor of open science, it should still be important to factor in time and costs. For people who are users of a device, they clearly don't care, they'll choose the one that best suits them. For developers, however, piling up may be counter-productive. There are million examples on software.
I do think that successful open projects are those that last longer. If one projects gets continuous funding for 20 years, it'll reach much further than if independent researchers get 20 years worth of funding
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