It depends on what do you prefer. Growing hydrangeas from cuttings is usually easy but requires monitoring and time.

https://plantaddicts.com/propagating-hydrangeas

It's not an either or question. Why don't you do both? Buy a few plants for instant impact and take cuttings for your own interest and satisfaction ... and, of course, to get free plants. In my world propagation is integral to gardening. We don't know where you are situated but in my region many shrubs can be propagated simply by sticking short lengths into the ground and leaving them alone. Forsythia, Weigela, Hydrangea, Currants, Spiraea, Box, Privet .... all will root this way.

Of the varieties you pictured and sounds like you are new to plant propagation, I'd buy the lilac and DIY the hydrangea.

I tend to buy a plant and use that as a stock plant in order to make more by cuttings, division or saving seed (although there are copyright issues with many hybrid cultivars). Gardening is such an absorbing, creative, egalitarian interest,..I can think of nothing else which explores such a range of skills, while being accessible to everyone. Unlike money, plants literally do grow on trees (and shrubs, perennials, annuals...).Don't put limits on your world - there are so many pleasures to be had from all aspects of gardening, regardless of whether you buy or propagate your plants.

I find both of these easy to root in pots of sand. They grow fast enough . Propagating plants can be fun and you can share cuttings with gardening friends.

@erasmus_gw I’ve never heard of rooting in sand! Would i need to use a growth hormone? Can I propagate them in water?

Lilac by nature is a suckering shrub and many new ones are propagated just by digging up a yearling sucker and replanting. They already have a root system so easy-peasy!

I had a double very dark purple lilac I shared with my neighborhood by this method.

@gardengal48 is this similar to separating hostas?

root cutting a shrub is nothing like dividing a hosta.. unless you mean you use a shovel ... to dig up the plant....

collected about a dozen lilacs over the years.. just by knocking on doors and asking if i could dig a small piece up... getting a bit of root.. i then potted them for the rest of the season.. then planted them in fall..

just fyi.. lilac is a flowering shrub.. there is a shrub forum ... the rules are different for perennials.. vs shrubs.. some of the defining reasons between the plants... once you learn how to ID .. or group the the plants .. then figuring out the rules should come easier..

i never messed with Hs... cant grow everything.. though we try hard to do it.. lol ..

ken

https://www.youtube.com/watch?v=FsmSvYskzgA&ab_channel=FlowerPatchFarmhouse