Pretty much anything grown from seed will be just an example of the species. Very few cultivars come true from seed wrt perennials and no woody plants that I am aware of. Cultivars are almost always propagated vegetatively.

How do they develop new cultivars, if not by crossing seeds? I suppose it is all volume related?

Sometimes new plants are intentionally hybridized but most of the time, they discover sports or seedlings that display unusual attributes and then grow them on and propagate them vegetatively, either by cuttings or grafting. And infrequently for woodies, sometimes by tissue culture.

in conifers and trees.. a majority of them are grafted ... and that is one reason they cost so much ... from the graft itself to saleable size.. could be 3 to 5 to 10 years.. depending on sale size ...

many originally show as weird branches .... and those are harvested... and grafted.. and grown for years.. to get more graft material... so it can take a decade to finally introduce the stuff in bulk ...

if you find newish stuff cheap.. that probably means that particular plant can be rooted from cuttings.. cutting the number of years invested up front ....

presuming the seed is just the plain old version.. those can be grown for 2 or 3 years.. and then used as understock for grafting ...

thats the kit and caboodle in 4 paragraphs.. very simple.. and you can spend the next 3 or 4 years.. getting the scientific version .. lol

lastly.. even if the seed creates a new weirdo ... you are right back to .. how do you make more of them ... and you start reading at the top of this post.. lol.. very vicious circle ...

ken

ps: the converse is let say...annuals... you can go from a precise pollen cross to flower in one year ... and might be able to replicate that on a commercial level .. maybe not ...