Regarding Chainlink itself, there seems to be almost no doubt that the system is reliable. LINK has also proven to be a good cryptocurrency, so most people dare to work with Chainlink.
Most of the things that people stumble upon when it comes to trusting Chainlink are specifically in the field of oracles. For now, these are still centralized, backed by real people and their own companies. It is therefore important that the people behind the oracles work reliably and accurately so that no mistakes are made in the agreements.
For example, if you want to sell your bitcoins when they exceed a certain amount, but the oracle already does it with a thousand euros less (for example due to miscalculation in exchange rates), the system automatically does something you did not want at all with all consequences of serving.
In addition, you need to be able to trust that the people and companies behind the oracles have only good intentions and that there are no companies with bad intentions behind them.
The image of the oracles can be improved when they are designed in a more decentralized way. If all goes well, Chainlink already seems to be working on it, but when we can expect it to turn out to be so is still unknown. Without a decentralized money system, one mistake could immediately upset the entire system, so investors would rather get their hands on it as soon as possible.