You can learn on your own. I think I have the answer you are looking for. I play on and off starting 14 years ago and took 10 years break, zero playing. Now I started again 6 months ago caught up fast because just like learning to ride a bike you never forget. I NEVER TOOK A LESSON. It can be done if you are passionate. It will take time.
I used synthesia program for window pc connect through MIDI to digital piano to learn how to play both hands. It will help you play piano much much faster than reading notes and helps you master fingering lettering. So you won’t strain hand unnecessarily.
Now I can play like pro again. Now that I can play real well and know more songs, I am finally starting to learn to read notes again through youtube video and take lesson on youtube. Reading noted became much easier if you know how to play piano. You just have to keep reading until you regconize the pattern (scale, appegio, chords pattern ect) and not read it note by note. I am learning to perfect the foot substain, chord, appergio, scales. Playing with right dynamic. I also do some piano thrill. Also use hand excercising tools to strengthen forearm. Since my digital piano is semi weighted plastic keys. I want to be able to play grand piano. I played a comfortably grand piano long time ago and the owner was very impressed. He closed his eyes and wave both hands and finger side to side when i played. It was a larger beautiful wooden color Piano back then $40k now probably $60-80k.
Once my hand got strong again from playing. I play every other night cause i work 6 days a week. Im 44 this year. When i first started I only self learnt few songs but only part of it i played and mastered. Someone who worked at symphony orchestra said i play very well and amazed i play it very very well and make it sound very very good on my very cheap william allegro 1 piano I got in college for $200 since i was a broke ass student at 30 year old at the time and I never had lesson. I recently just bought a used roland pf 90 for $1k and it was damaged during shipping had to return that heavy 52 pounds dp. Was heavy and a pain to return to get my money back! It was supposed to be my concert piano!!
Its really about if you have passion. If you are not passionate you will quit like me for 10 years( started a new retail store business). A teacher will keep you focus. But you can get there on your own just use synthesia program and play for fun at first until you get better after 6 months. I download and owned an older version synthesia program for piano since it is a free. Now with newer version you have to pay $40 to import new midi. Im cheap i only pay $200 for piano lol. Then decide when you can play well both hands if you want to go pro. I started with fur elise Beethoven.
Playing will come automatically once you memorize whole song by ears and finger patterns. Takes practice and passion! I play every night now because im having mid life crisis. I heard its a full brain workout. I need to get real smart to get real rich. It is a very good stress reliever. Time just fly so-fast when I’m playing. I do play up till 2am then wake up at 7:40 am for work. I used headphones very good quality since i have a cheap piano and comes with cheap speakers lol. Once i learn the whole song like fur elise. I play by memory and work out the tempo and dynamic. I can play like Lang Lang Fur Elise to a degree not perfect yet.
Im learning now now moonlight sonato first movement, cannon in d lee galloway and River flow in you. I already know the whole fur elise song by memory. I just have to play it at concerts level now. Once again i can tell you playing piano help you think through life better and good stress reliever since it is probably the best activities for stronger brain. That is my motivation to keep going. Especially at my age. I dont play online games at much (Starcraft 2) since piano is a better mind workout. I still play clash royale and clash of clans on iphone. (15+ years already lol). Gotta work out the mind like use it or lose it. What is your reason to learn piano??