Common computer hardware such as 4GB of RAM and common CPUs (general CPUs, not for supercomputing) cannot process the data quickly.
You should use a database if you imagine you will frequently record data until you may have a huge amount of data.
If you expect that you need to enter some data every fifteen seconds, you should consider using a database.
Microsoft Excel and LibreOffice cannot handle a very large amount of data. I am talking about general purpose computing. I just have a common Intel CPU. I just have 4GB of RAM.
If you imagine you will need to save a large amount of data, no office productivity suites can handle this situation.
Only use a database. A database can handle a large amount of data.
Common databases are MySQL and PostgreSQL. If you decide to use either one, it will be tricky to migrate from one to another. Please decide with your wisdom.
In my experience, different versions of MySQL were or are incompatible, meaning that upgrading from one version to another might or may cause data loss. For PostgreSQL, upgrading did not cause any data loss in my case.