That much is correct, to the extent that the evolution of SSwas sparked by the need for countereasures to interception/jamming of signalling required by military command and control comms. It has evolved from a countermeasure to intelligent jamming into a countermeasure to dumb jamming, i.e., noise (which may originate from intelligent or natural sources), in the comm channel. It is well suited to low power comm systems - a tradeoff to the brute force approach of countering interference by overwhelming it with transmitter signal power. You can enhance robustness of a comm link with power, bandwidth, or time, or some combination thereof. SS does it with bw and/or time, vs more power. More power would work, but has some costs and other unpalpable aspects too. SS doesn't overlay well with existing comm systems that require dedicated (or at least well coordinated ) use of their allocated, rigidly fixed parts of the frequency band allocated to a type of service. There is more to the band allocated within the spectrum to SS comms than a narrow frequency slot, whatever part of the overall spectrum the band occupies - there are strict protocols required and in place, including limits on power output, to ensure that users of the entire band allocated don't step on each other and can share the resource as peers in other regards. It's an alternative to assigning dedicated portions of the band to each user, which requires coordination between users, e.g., temporary 'rights' to a piece of bw by such customs as claiming it via use of the familiar pin board. As others have mentioned, eliminating that custom in itself has probably made a significant contribution to avoidance of interference and consequential mishaps in our hobby.

Again fwiw, frequency hopping is a subset of SS technique. Not materially different from the other most commonly used SStechnique of time division. A gent named Fourier tells me the two are equivalent, and he devised a transform algorithm to conveniently switch aspect from the frequency domain to the time domain. Go argue with him, I'm getting weary of this.