If your technology decisions are being made reactively, one fire at a time, then yes, you need a strategy, but probably not the kind you are picturing. For most growing businesses a technology strategy is not a thick document. It is a short, ordered list of what to fix, what to leave and what to do next, so you stop spending money on the wrong things.
Signs you need one
You likely need a technology strategy if any of these sound familiar. You are not sure whether to fix a system or replace it. You keep buying tools that do not talk to each other. A single person leaving would take critical knowledge with them. Or you are about to spend a large sum and have no way to judge whether it is the right call.
What a good one actually is
A useful strategy answers three questions in plain language. Where are we now, honestly. Where do we need to be in the next year or two. And what is the shortest, cheapest path between the two. That is it. If it cannot fit on a few pages and be understood by someone who is not technical, it is not doing its job.
The common mistakes
The usual mistakes are buying technology before deciding what you are trying to achieve, copying what a much larger competitor does, and treating strategy as a one-off event rather than something you revisit as the business changes.
A technology strategy is not a sales document for a particular product, and it does not require you to rip everything out and start again. Most of the time the right answer is to keep more than you expect and sequence the changes so the business keeps running.
Working out that ordered list is exactly what a Technology Discovery and Blueprint does. It is a short fixed engagement that leaves you with a plan you can act on.