Don't over-thinking your hosting. No need to jump to EC2 or CloudFront.
Much like the selection process of SQL vs NoSQL, where to put your front-end application can be a minefield. It can build in costs that are not needed, speed up or slow down deployment and is often driven by the experience of your developers.
This is not a comprehensive list, but is a good sampling to open up some options that are free, scalable and easy to use. Yes, you can split your API hosting from your UI hosting.
Github.com is rock solid. When Github has an outage the entire world knows it, because we can not get to our code or deploy. The GitHub servers handle millions of transactions per second. Because of this base capability for hosting git repositories, their hosting services for static content are extremely table front-end applications.
What Github Pages does not offer is serverless functions, which just means your backend code (API endpoints etc) needs to be hosted somewhere else.
We often think of Github pages for blogs and code documentation, but it supports CNAMES and domain Apex records. It also provides SSL certifications by default to enable HTTPS.
Heroku is Amazon Web Services (AWS) but with a devOps-free wrapper (or it was). For many years this was over powered solution for hosting a front end. It has a strong CLI and works well with deployments from CI/CD processes. It is a bit long in the ‘technology tooth’. It’s been around a long time, and since Salesforce purchased it, the hobby (free) options have gone away.
Render.com is the new hotness! It’s the best of all the edge hosting options but with a strong focus on the skills and challenges that front-end developers know the best. And it offers a free layer, for public repositories. Since most starts do not have enough initial load to trigger the payment levels, it’s a great place to build. Their setup process works well with GitHub Actions, and your developers will find the deployment process mirrors their development tooling processes.
Fly.io is a docker-centric hosting solution. This option has a strong hobby pricing option, so unless you exceed 5$ a month, it’s free. And most early-stage startups, this is a great solution. This solution is great if you expect your team to need microservices or to move toward Kubernetes.
Vercel is designed for hosting UIs on the edge cloud. It’s designed to work well with the specific configurations needed for front-end apps. NextJS works out of the box. Their jump-start libraries make spinning up UI solutions an easy learning curve.
While Github.com is my go-to, for now, Firebase Hosting has been my default for a while now. It’s turn-key easy. It works well with CI/CD processes, and can even be deployed directly from your laptop if you want to get changes live quickly. You can use just the hosting service, and ignore all the other GCP goodness. You can mix and match the solutions that site under the umbrella of Firebase; auth, functions, hosting, AI etc.
All these options are secure. For the past five years, SSL certificates have become free and standard. So no cybersecurity concerns with using any of these. If your deployment processes are managed from git repositories, then it's very solid.
* AWS EC & CloudFront Why, why why :) Most websites do not need load balancers and CDNs. The cost of DevOps does not outweigh the other options above. Both AWS and GCP best practices lead startups to over provisions long before business or scale is an issue. Scaling back can be painful when a startup needs to cut cloud costs.