One word: math.

Bitcoin is based on math. It has finite supply, known, stable rate at which new coins are mined and has been following a number of curves and staying within certain averages since it was created.
You can find people explaining the math behind bitcoin in various articles and videos. There are only 2 possible outcomes for bitcoin which are growth or death because halvings make sure the value will grow and with it there will be greater interest and adoption. You can see it happening with the number of companies and even countries getting interested in bitcoin.

If bitcoin continues to exist it will have another halving and it will have more of its supply lost forever, making it more and more scarce. If it's still there in 2 years, you can be sure it will be worth more than today.

People focus too much on highs, but it's really the lows that tell a story. Highs are very volatile and jump all over the charts, but lows are showing a slow and steady growth. I don't know how low we will crash from here but I'm ready to bet that we will never again see 2020 lows.