My guess is a reference to Gold Priority Rewards, which are, obviously, not available to the OP as a Silver.

Nonetheless, likewise, I've never really struggled to spend Avios. I achieve this by being flexible on times and destination, if that's not possible for the OP, then I can see why spending would be more difficult.

Earlier this year, HfP ran an article with a rough estimate that 85 billion Avios are redeemed on BA flights every year, if that's even close to accurate it suggests that plenty of people are using them successfully.