A good tech is crucial to any coin.
First let's begin with some antithesis, examples of bad coins with good tech.
Algorand - amazing tech made by knowledgeable people with good use cases. Bad tokenomics and management leading to ATH at launch and dipping ever since.
BAT - amazing Brave browser, good idea. Bad implementation of the token, no native wallet.
Now, looking at the above example underlying cause of decline for the above example is not the bad tech but either poor tokenomics or management.
However, bad tech or rather lack of use cases for the coin is not sustainable either.
At present there are so many coins and tokens in the market that its no longer enough for them to be just being a Bitcoin alternative.
Another misconception people have is that Crypto is a Zero some gain, that someone has to lose for you to gain. No, that is not true. If you buy a coin at $1 and sell it at $10 then that does not mean the next person is at loss he got in at his time you got out at your time. The price can keep raising with diminishing returns as the value the coin increases as the use cases of the underlying tech improves.
Case in point, Ethereum. Smart contracts and native tokens, good tech that keeps improving.
Moreover, what problems is the new coin is solving the most important question. Like Nano solve the problem of fees and transaction time. Furthermore, with good tokenomics and development around coin is paving the way for its adoption.
In this regard, even if there are no smart contracts on Nano, there are market places like NanoMart, Games like quake, CS:GO, Rock Paper Scissor, there are Swaps like Kuyumcu and many more things that make up the Nano ecosystem and brings utility and use cases to the coin.
Therefore, if the coin has good foundations a.k.a good tech then it is bound to raise as it keeps providing more and more value to the society.
Unlike any other coin which is just hyped, they can fall as soon as whales dump their holdings.