Here you can see the size of the UTXO set over the past 5 years: https://statoshi.info/d/000000009/unspent-transaction-output-set?orgId=1&refresh=5s&from=now-5y&to=now

It completely exploded in 2023. No wonder your 8 GB RAM Pi performs poorly on a 11 GB UTXO set.

You could still try increasing the value of dbcache= in your bitcoin.conf to a number of Megabytes that still fits in your memory. Might improve performance a little.