"Just use BigQuery" is the advice many "GA4 experts", who have never even written a SQL query or dealt with databases are giving these days.
I am all for using BigQuery with GA4 data because I see the power of using GA4 data in BigQuery and have advocated using it ever since GA4 released the feature to send the data to BigQuery. (see Unleashing the Power of BigQuery and GA4: Why Marketers Should Use These Tools Together).
While sending the GA4 data to BigQuery is easy (see the post, GA4 BigQuery Export; Why and How)
However, using BigQuery is not as simple as it sounds. BigQuery does not have a reporting interface so you have to either use a data visualization tool such as Looker Studio or write SQL queries to pull the data.
Looker Studio will only help up to an extent. A lot of smaller/mid-size sites will not have to deal with the thresholding limits, so if your plan is to use BigQuery as a replacement for the GA4 interface then you won't even need data in BigQuery. You can just point Looker Studio to GA4 and you are done.
Organizations that are serious about data-informed/data-driven decisions will need to write SQL queries to fully utilize the value of GA4 data in BigQuery.
Writing SQL queries to help answer business questions is not a small task. You can't do that without properly understanding business needs, data structure, BigQuery, and SQL.
In addition to GA4 data, you will also need other data such as CRM, 3rd party data, etc. to fully understand customer behavior, product performance, campaign/ad performance, etc. This requires specialized skills in creating data pipelines to bring other data sources, dealing with APIs, architecting data storage, tables, query speed, etc. I don't expect "web/digital/marketing" analysts to know these.
However, if you are going to be pushing in the "just use BigQuery" direction then make sure you have access to proper skills/resources before opening this can of worms.
If you would like to explore GA4 and BigQuery then don't hesitate to reach out to support@optizent.com or fill out the contact us form.