Answer: in most cases, yes
Explanation: Think about it in terms of a simple company, like a lemonade stand. Your variable costs will be the ingredients to the lemonade - water, sugar, lemons. If you sell more lemonade, you need more of those ingredients.
The wages for your employees are more fixed. If you sell no lemonade a certain day, you still needed to pay your employee to be at the stand. If you sell a lot of lemonade in one day, you were still able to do it with the same employee.
Over time, of course, if you expand you will need to hire more employees. But growing fixed costs to enable expansion does not mean those costs need to vary with your sales. You can absolutely over-expand and end up with too many employees for the amount of lemonade people are willing to buy.
There are little details you can nitpick here. Commissions for lemonade salesmen will vary with sales. But at a high level, you should think about wages as fixed costs.
