"Not template-heavy" mainly just means not library code. Templates, like most important C++ features, are mainly there to enable writing better, faster, more powerful, and less easily misused libraries than you could have, without.
Failing to use good libraries would be a mistake. A library is probably faster and less buggy than what you would code in place. Time spent improving libraries is amortized across all uses, so there is more of it. This is very evident in heavily used libraries.
You might not notice the templates much, but they made your experience using the library better. They have tailored the generated code to be optimal for just the way you are using it, instead of doing what would be just OK for all uses.
It can also mean not overusing libraries, not overabstracting prematurely, seeing if you can simplify the high-level design of the program to not rely on complicated compile time magic so much.
There's probably a good balance to using templates where they improve QoL but there's only very little code with those mess of < and > that tend to produce unreadable error messages. But a lot of "modern" C++ I find browsing on the internet way overuses templates IMO.
I could be considered a masochist for still writing plain C, but I find it very convenient just having one compiled (not optimized to death) version of code that is parameterized with runtime parameters (mostly sizes, sometimes alignments, rarely function pointers) in most cases. I find it also better for modularity if the library and container code is type-agnostic. It also builds faster, often much faster. Doesn't work for non-POD C++ classes, of course.
C-Pointers are often all the "generics" I need, sparing me to type out almost all of the repetitive size calculations. And even that (array access) gets rare as the projects grows more and more structure.
Failing to use good libraries would be a mistake. A library is probably faster and less buggy than what you would code in place. Time spent improving libraries is amortized across all uses, so there is more of it. This is very evident in heavily used libraries.
You might not notice the templates much, but they made your experience using the library better. They have tailored the generated code to be optimal for just the way you are using it, instead of doing what would be just OK for all uses.