Look at all Irish Airports, not just Dublin, as all have flights to the sun, mainly on Aer Lingus or, especially, Ryanair-
Cork- Lanzarote, Tenerife, Alicante, Barcelona, Fuerteventura and Gran Canaria
Shannon- Alicante, Faro, Fuerteventura, Funchal, Gran Canaria, Lanzarote, Gran Canaria, Tenerife and Palma de Mallorca
Kerry- Alicante and Faro
Knock/Ireland West- Lanzarote, Tenerife, Alicante and Palma de Mallorca
Dublin- Alicante, Barcelona, Faro, Gran Canaria, Lanzarote, Tenerife, Fuerteventura and Funchal, also (seasonally) Palma de Mallorca
(also, further afield resorts in Greece and Turkey)
But also don't forget that Ireland has many fine beaches, although many may be off the typical RS forum tour of Ireland sort of itinerary- https://www.theirishroadtrip.com/best-beaches-in-ireland/
It is also possible to have a beach holiday in Dublin- there are some excellent beaches in the North Dublin suburbs- using the North Suburban rail service to commute into the city of Dublin.
Donegal is the only Irish Airport without flights to the sun