Glad you are planning to use pega cloud, instead of directly answering, let me list some of the pros and cons (note: this is not an official list but my own take) - it should be pointed out that pega cloud runs the same image as that of on-premise deployment.

Pros:

No need to procure your own hardware/software before you can install pega software.

No need to hire pega/underlying hardware/software administrators - significant investment up front - instead, pega cloud instances are managed by pega internal experts with deep knowledge on all tiers of the applications (app server, database, presentation layer, etc).

No need to worry about installation/upgrade, will be handled by pega cloud/product experts as well for the most part - pending your contract details.

Proactive performance tuning by pega experts should you choose to utilize PDC.

Cons:

Only support tomcat/postgresql platform on war deployment - this means that there is no support of ear deployment, see this link for details: https://pdn.pega.com/choosing-between-ear-file-deployment-or-war-file-deployment. Also the choice of application server and database server is only tomcat and postgresql respectively.