Gain of function research is as dangerous as chimeric research.
Essentially, it is the same. The Bat coronavirus segments spliced into the SARS backbone contain the spike protein that enabled the SARS Cov-2 virus to infect lung cells and epithelial airway cells more easily using the ACE-II receptor, and turned a relatively easy to contain but deadly disease (SARS) into a pandemic.
By creating the chimera, function
was gained. The disease spread more rapidly, even if it was less deadly, something which seems to be common in viral evolution.
For the purposes of creating economic havoc, selling billions of doses of a useless experimental 'vaccine', and stealing the election of 2020 (along with a plethora of probes into the tolerance for totalitarian edicts of the American People), the gain was sufficient, especially with the mass and social media pimping panic to the masses.