I often wonder if all the frustration is worth it, for a £5 Amazon voucher every month.
Starting to feel a little 'Penny wise, mental health foolish'.
You are correct.
Many people posting here seem to think that the various Microsoft rewards are like a savings account. They are not. People will earn much more by getting a job.
The Microsoft rewards are actually a way to encourage people to use Microsoft products, by adding a way to earn small rewards. Very many retailers do this, with loyalty cards or by asking you to sign up for an account on their website.
For those who think instead that Microsoft rewards are a way to earn money, it's in their interest to game the system so as to accumulate the most rewards possible. This in turn forces Microsoft to implement increasingly arbitrary and draconian restrictions to prevent misuse. Unfortunately, everyone suffers from this.
Nor is Microsoft the only company in this predicament. I'm sure you're aware of websites that show people how to misuse loyalty programs to extract more benefit than companies originally intended. Before it became unpopular, 'couponing' was an example of this.
If you earn Microsoft rewards, claim them as soon as possible. And if your claim doesn't work out, oh well. But no one should look to Microsoft rewards as a way to earn serious benefits. That's not why it was put in place.