The short answer for an adult learner is a probably no in my opinion, although you do have the choice.
Music is a form of communication from the person/people who wrote the music to the listener or person learning to perform the piece.
Music in written form is simply another tool to communicate. Traditional written music is the accepted norm among musicians to communicate in a universal, accepted way. The music will tell the performer the key signature, time signature, tempo and feel very quickly. The musical notes refer to the notes on the instrument and will also show the length they should be played. Rests or gaps are also communicated in addition to repeated parts or skipping to a new part later in a piece. It’s an efficient language, but daunting to the beginner.
In effect, it is the same as learning a foreign language. My own musical reading is basic. I learnt treble clef at School (generally the notes played with the right hand), but base clef (generally the low notes played with the left hand) is still new to me and a challenge. Focusing on both parts at once is also tricky.
I would certainly recommend a child to learn to read music when starting the piano or any instrument. They have an ability to pick things up easily at a young age and they also have time on their side. However ensure they are taught by a competent musician.
For an adult, there is no requirement to learn to read music when learning to play. There are various other ways to communicate the notes that should be played, the tempo, the key etc.
These can be written down or memorised. I tend to memorise pieces and this simply comes from repetition. Even if I study a piece from a traditional music manuscript, I tend to learn and memorise the notes rather than read from the sheet each time. Some traditional teachers would not recommend this, but I find it ok and it’s good to keep the memory tested.
Shawn Cheek’s method of letters on a white board either as single notes or stacked for a chord works for me. He communicates the rhythm for each hand and when notes are played together by both hands or independently. The age of the video on You-Tube or Udemy has changed the way music is communicated and the learning process of the piano.
Will traditional music manuscript writing be extinct in years to come? I doubt it, as it still presents the most efficient and universal method of communication, but adults now have a choice whether they simply would like to enjoy playing the piano without the added challenge of learning a new language.
By all means make your own choice and having the skill of music reading can never be taken away from you. It will be an extra and lengthy challenge for an adult, but this may be appealing. If you are completely new to the piano, I would advise getting some enjoyment from the instrument first and learning some songs before learning to read.
Feel free to add your views.
Here’s a good website giving you a quick look a music reading if you do decide to take if further….
Here’s another good website.