Plenty of nonviral bacteria-eating entities exist, and would become more numerous
Plant and antibacterial defenses aren’t viral-based
For the bacteria to compete in the same niche as unmodified versions it has to fulfill a similar ecological role: photosynthetic cyanobacteria with altered DNA would still produce oxygen and provide food
It couldn’t benefit from exchanging genetic material with other kinds of bacteria
That advantage only goes so far:
Plenty of nonviral bacteria-eating entities exist, and would become more numerous
Plant and antibacterial defenses aren’t viral-based
For the bacteria to compete in the same niche as unmodified versions it has to fulfill a similar ecological role: photosynthetic cyanobacteria with altered DNA would still produce oxygen and provide food
It couldn’t benefit from exchanging genetic material with other kinds of bacteria