Realistically speaking, many are unable to retire comfortably with BTC fluctuating rates.

Currently 10 BTC and 100 ETH are roughly 282,000, and 180,000 dollars respectively. Combine both and you're still short of 500K assuming that the bullruns don't further dilute your holdings. That is if you are able to continue buying while maintaining some spare cashflow for daily expenditures.

I'd just go with whatever amounts that suit my fancy. There are other assets that will continue to appreciate so the amount of BTC don't matter to me.

10 BTC and 100 ETH which is not small money in my country here, but you can calculate what you see as enough depending on your financial status and what you earn monthly, weekly, or annually. For an average guy like me, this amount is really enough for crypto retirement, adding to other forms of assets that you might have accumulated before your actual retirement date. And if you are lucky enough before retirement, both coins might have doubled in price, which will be a lot of money compared to what they're currently worth.

for now, 10 bitcoins and 100 ethereum is a lot of money. we assume that bitcoin and ethereum prices will be very high in the future. meaning, you need to have a lot of money to accumulate that amount before retiring in search of bitcoin or ethereum. actually it's a good value, but if that's your target, then you need to set it up from now and take advantage of the bear market to get a cheap price. Personally, I don't know how much is suitable for retirement, but as long as I can still earn from it, I will continue to try to make it.

It is extremely risky to bag hold altcoins in general, it is even riskier if the altcoin is centralized, flawed and most importantly has an unlimited supply such as ethereum. In 10 years, it may not even be around let alone be worth higher than this. Not to mention that the past 5 years that ETH has been dumping consistently (from 0.15 to 0.06) has proven that it has no long term potential.

As for bitcoin, the way I wouldn't rely completely on bitcoin for retirement. In 10 years with the way inflation is going and if the adoption is slow and price doesn't go that high you may not have enough bitcoin to retire comfortably. In most countries the cost of living is already huge and is increasing fast.
It is best to diversify into other assets and I mean real assets not altcoins.

That's a tough question and depends on a lot of things. Where do you live, how much do you spend, do you have other investments and etc? You're the only one who can answer that question, especially because no one knows how much BTC will be worth in the future.

What kind of lifestyle will you take?
The calculation would be equal to (average annual spending+6% of average annual inflation)*10 years. In my neighborhood, at a low-medium economic level, it's $200 monthly fees so that would be $2.64k a year or $26.4k for 10 years of life spending.

Then 1 bitcoin will be enough if you live in my country. The adjustment will be easier if you can reduce some unnecessary cravings.

My plan is not to retire. Even if I accumulate many millions, after some time traveling and so on, I would work but with my own projects. People dream of having so much money so that they don't have to work that they are not aware that those who get it, one of the following two things happens to them:

1) After a season on the yacht and playing golf, they get bored and decide to go back to work creating their own entrepreneurial projects.
2) They end up turning to alcohol and drugs, which usually has a bad ending.

This talking about young people, if you are 60 or older, it is more normal to retire and dedicate yourself to a contemplative life without getting bored or ending badly.

I still want to collect more bitcoins for now and even if possible, I want to have more than 10 BTC and more than 100 ETH. But I don't know when I will be able to have that amount of BTC and ETH but I will keep trying hard.

Maybe in developing countries, having 10 BTC is more than enough to be passed on to posterity and they will not lack anything in their life especially if they can develop their skills and abilities to add more bitcoins. And I think more bitcoins would be better for us because there is a possibility that bitcoin will become more expensive.

In general, the more bitcoins you accumulate, the more comfortable you will feel in retirement. But I think it would be too risky to concentrate all your retirement money on a volatile and risky asset like crypto. I agree with what pooya87 said, you should diversify your assets with assets other than crypto. In case, if your crypto investment crashes and you don't diversify your assets then your retirement dreams will disappear. Don't forget that bitcoin or ETH are both very risky.