In general, there should not be a significant material difference between liquid detergent formulated for top load washing machines and those designed for front load washing machines. The main difference between the two types of machines is the way they agitate the clothes during the wash cycle.
Front load washing machines use a drum that rotates horizontally, and they rely on gravity to move the clothes around. They typically use less water and are more gentle on clothes, as the drum's tumbling action is less abrasive.
On the other hand, top load washing machines have a vertical drum and typically fill up with more water. The agitator or impeller in the center moves the clothes around during the wash cycle.
Now, some manufacturers might label their liquid detergents as "specifically formulated for top load" or "front load" as a marketing strategy. The intention is to target consumers who believe that using a detergent labeled for their type of washing machine will provide better results. However, as you've noticed, in many cases, there may be little to no discernible difference in washing quality between the two types of detergents.
Both top load and front load washing machines can effectively clean your clothes using a standard liquid detergent. The key is to use the appropriate amount of detergent based on the load size and the level of soiling. Using too much detergent can lead to excess suds, which might be more of an issue in front load washers that use less water.
Ultimately, the choice between using a "top load" or "front load" labeled detergent is not as critical as using a high-quality, effective detergent in the correct amount. You can use either type of liquid detergent in your washing machine without major concerns about performance, as long as it's compatible with your laundry appliance and your clothes are coming out clean and fresh.