Of course, plenty of them, when I had just 1, then 2 and then 3. Half of the time I was alone before DH would join us at our holiday home. So at times, I would be alone with a baby, a toddler and a 5 years old.
It all comes down to defining what you call holiday.
Sleeping by the pool or browsing your phone happily and undisturbed , nope , not going to work.
Enjoy them , play with them, do sandcastles, fetch thousands of buckets of water from the sea, going on a sea shell hunt, making up stories about pirates, cast aways ., you are going to build the ninja course, ....
The only difficult part is carrying stuff, sun umbrella, towels (including the one you stand one while drying child) , a beach bag with cream and water, and a big net filled with beach toy and dragging a stroller at the time.
Holiday will reflect the dynamic you have at home. You have a tantrumy child, never happy , holiday will be tough. You have a normal child, you may have the best time ever.
Bring buckets (at least 2), a couple of spades, some cheap toy cars (10?) - because you will be building the biggest ever car circuit and will attract all the kids within a 100 mt range - , small ball the size of pingpong ball - ditto as above, a circuit - , a bigger ball to play soccer, arm bands, ...
Use a beach umbrella anchor so you won't have to chase your umbrella if windy and you will be able to keep it open.
And don't bring crap to the beach, only fruit. Rubbish food will make kids cranky. As will screens. The second you hand your phone to a child, its imagination and creativity is down the toilet.