Realistically speaking, Bitcoin's dominance actually should be higher than 80%. Knowing that with A LOT of altcoins, most of the total supply(we're talking 50-80%+) are actually held by the development teams, which makes their total "market cap" really inaccurate and unfairly calculated.

Going with the CoinMarketCap Bitcoin dominance metric though, I think it's kinda unlikely for Bitcoin's "dominance" to go as high as 80%. The cryptocurrency markets as a whole is still a huge casino-ish market, and I really don't see that going away any time soon.

Ethereum's share of the market is 13% right now, it could drop to 10% like it was not long ago, but it's unlikely to go any deeper. That already puts Bitcoin's realistic short-term share at 90% max. Tether has 2.5% of the market - if it won't implode, it could only continue taking more and more of the market as more USDT is printed. Aside from these two coins, I don't see any other coin that fundamentally should be as high as it is now. The rest of the market should amount for 2-3% at most. So, Bitcoin could achieve 80% dominance if alts crashed really hard, but so far there's still a lot of people willing to gamble on alts, so it's probably not gonna happen, no matter how high Bitcoin gets.

What you should worry is whether you get a profit from selling your coins at a certain price point. I still haven't done any trading so I do not mind that the dominance goes whichever percentage. I do agree with bitcoin against the other shitcoins not that important because I see those shitcoins as leeches that mooches off the benefit when bitcoin prices go high.

Bitcoin dominance is now falling from the critical support and therefore we are seeing this massive pump in the alts. We have a mini bull run here where all the alts will pump until we see big movement in bitcoin either in upwards direction or downward direction.

The number you are looking is not bitcoin's "dominance", it is simply a ratio of bitcoin's market capitalization and the total market capitalization of thousands of shitcoins.
Since market cap is calculated simply by multiply supply by price and shitcoins can easily create any supply value they want and they have done that, the total supply (hence the total market cap, ie the denominator) is gigantic hence the ratio is close to 70%.

As new shitcoins are created (like the ICO mania of 2017) or the existing shitcoins have or create large amounts of supply (like the 72 million premine of ETH, or the out of thin air issuance of XRP) the denominator grows and the ratio goes down. But as these shitcoins inevitably get dumped their price*supply aka market cap goes down and the ratio goes back up again.

Actually in my own idea the dominance could and should be much higher than 70 percent. However, since we are heading to the alt season, we were expecting falling of the bitcoin dominance. on the ta side of the story, the dominance is fallen down to the key support area. I believe that's the relation between bitcoin dominance and the alt/shit coins.

Bitcoin's dominance will change as per the market situation and yesterday it was around 68.6% approximately, if Bitcoin pumps further then more users will shift their altcoin holdings into bitcoin thus increasing the market dominance and vice versa, but we also need to understand that crypto is more than just bitcoin and it's not a good sign for some trustable altcoins if they don't even reach half way in terms of market dominance. This proves that Bitcoin cannot be dethroned as king of crypto.

it is natural to see the potential of bitcoin now is very extraordinary and the price of bitcoin is high. although bitcoin dominance will definitely experience a correction against altcoins, bitcoin is still too strong in that position, so my advice is to stay positive and buy bitcoin

as of last months bitcoin dominance has risen up to  70% and still way to go to reach the possible 80-90% dominance. If bitcoin price will not go down this month probably bitcoins will reach higher than $40000/Btc and it would be good for investor that they may gain more profit after investing in bitcoin.