Technical analysis focuses on price data history to build the basis of its prediction, looking at previous trends, demand, supply zones, etc.

You are absolutely right . Besides above mentioned points , we can look for some chart patterns formed in past and expected to repeat in future and behave in a similar manner as that of past . Basically represent the psychology of the traders and actions taken on the basis of that and we expect humans to behave in a similar manner on different occasions based on their psychology.

Hence it's advised to always have multiple layers of confirmation before executing a trade idea.

That's absolutely true and wise advice .

This could be disastrous for traders as fundamental data tends to push prices hard.

Yes fundamnetal analysis is very important especially for long term traders.

Good luck