You can, most networks just decide not to. Broadcast TV (which hasn’t really existed for I think more than a decade now) had restrictions about swearing (and other content) enforced by the FCC as it used a public good (RF bands). Cable TV (and now streaming services) are and pretty much have always been unregulated.
TV Networks, being companies trying to make money, opt to self censor so as to appeal to the largest number of viewers, but that isn’t anything to do with the government, it’s 100% a business decision.