Ruger, for the most part, plays to its strengths--their subsidiary is one of the finest casting companies in the US--
https://www.ruger.com/casting/index.html Bill Ruger realized the skilled worker force relying on hand fitting and polishing that established gunmakers had --Colt, Smith and Wesson, Winchester, etc. was becoming unaffordable. In part, the GCA of 1968 was promoted by US manufacturers to get a breathing space from competition across the world via milsurp imports and cheaper firearms.
Thus, Ruger realized that improvements in castings meant that he did not have to have the expensive forging and machining operations of the old line gunmakers along with their expensive labor force and expensive production techniques. So, Ruger's designs soon relied on castings and minimal additional machining which saved labor and material. When you pick a manufacturing technique, it will constrain design to some extent.
Frequently, I see posters wanting the hand fit and finish of the firearms of yore--from say the 1900's to 1950's but they want it at today's mass market prices with forged and finely machined and hand fitted parts. Perfect examples are Garand receivers versus the ubiquitous AR lower receiver--which is easier to produce at a lower cost in labor, machining, and materials. The spotty reputation of the reproduction M-1 Carbines is another example--one repro will work fine while the next, not so much and the fit and finish are notably inferior to the real McCoy. But, if the Garand or M1 Carbine were priced with today's costs in labor and materials, you would spend a lot more than for Bill Ruger's firearms.
Injection molded stocks versus classic wood is another example. The Ruger American in a poly stock is superior to a lot of rifles in accuracy, durability, and accessorizing than the ye olde Mauser, Springfield, Winchesters, etc. of the golden age of firearms--but these will always leave some folks cold that like traditional bluing, hand polishing, and wood stocks.
Bill Ruger was no John Browning, but then again, John Browning was no Bill Ruger. Browning did not create from scratch or run a successful firearms manufacturer from a puny upstart into a major player in the industry which bypassed the market share and profitability of far older corporations with storied names and history. Browning's genius was in designing firearms that fit the technology and production techniques of his time. Ruger's true genius was in manufacturing processes and then designing the rugged dependable firearms that took advantage of it which could be sold at a good profit at a price that average Joe could afford. If Ruger's designs appeared on the exterior like those of past firearms and thus appear derivative, the innards and productions techniques to make and sell them to the masses are much less derivative.