High number of downloads doesn't mean it is safe and secure, apps with 100 million even banned in some countries due to security issues.
I don't know where you get this ideal from but I'm sure those 10 million users have wallets and sensitive files on their phones too and from the 40k reviews nobody complained of hacked wallets or spyware.
Stop standing on the existing protocol and try some research yourself.
You never know where your data can be misused but sure all of them will be collected and may be used already or in the future.You need to research yourself first about the risks involved when we give access to such apps, if you are going to trust then just because they have a high number of downloads doesn't make sense. Data stealing is everywhere but some companies use it for their own purpose so they become more popular than others.