I am in the same book. Booked the family of 4 all over the world during school breaks and summer holidays for nearly 20 years. Just before the pandemic in 2018 or 2019 I noticed that things were getting harder to Europe especially with Oneworld. (However I exclude British Airways on this as I don't like paying the exorbitant fees) But I was still finding pretty good Star Alliance availability with LOT, Swiss, Austrian)

However add the pandemic. Airlines have drastically reduced capacity also pent up demand in some markets, and uncertainty as what is the next curve ball Covid will throw at us. I presume that things will improve somewhat but the "good ol days" might be behind us. When I started in 2000, I was excited because I could book domestic first class for 25k miles even during holiday times when domestic F fares used to cost as much as $3000. Today I rarely see domestic F for 25k but that is alright because domestic F is so cheap that I tend to buy it if I want to fly it. What I look for 20 years later is Trans Atlantic J for 50k - 85k miles. However as the OP mentioned is getting much more difficult. But on the bright side I guess is I have now flown on sub $2000 trans Atlantic J flights and see more and more of those and less and less of point redemptions.

Unfortunately I am sitting on a boatload of airline miles but I am not sitting on a boatload of cash. Is this the end of the miles and points game? Not sure yet but things are definitely pointing more and more in that direction. I see availability in the off season and also some last minute availability which might be where points will really become useful in the future.

So Europe in October or February I might find good availability with points, but Europe in July or August you might be looking at cash back points and following discounted premium fares.