It's hard to make a suggestion here as your use case isn't clear enough.
Use BigQuery if you want to replicate your probably on premise Oracle and Elasticsearch databases so you can profit from the speed of BigQuery. You can do the replication via Google Cloud Functions. Your Google Sheets can be connected to BigQuery and BigQuery can easily be connected to DataStudio.
If you do data science on the data there would be BigQuery ML and Google Colab that would fit into your stack.
In case you do BigData analysis you can go with Apache Spark if you have enough resources (on-prem or Cloud). I suggest you to use a Kubernetes backbone for this as you only reserve the resources when in use and the cluster can be used for other stuff as well.
For dashboarding find your preference and the preference of your audience with DataStudio, Tableau or Apache Superset