Please consider the following:

• consider having driver 2 times bigger than worker,
• check is S3 in the same region, is communicating via the private gateway (local IPs),
• enable S3 transfer acceleration,
• in ingestion please user autoloader as described here https://docs.databricks.com/data-engineering/delta-live-tables/delta-live-tables-data-sources.html
• increase c loudFiles.maxBytesPerTrigger and cloudFiles.maxFilesPerTrigger autoloader options
• analyze parallelism using Spark UI (every CPU should process 1 task at the same time so if you have 64 cores, 64 files should be processed simultaneously)