Companies rarely buy other companies in order to make buyee's product better, they buy them to boost the buyer's business or at least remove competition.
They don't buy in order to make the buyee's product better, but continuing to improve the product may be necessary to realise the value of the purchase particularly if regular updates and improvements are a big reason that customers stay with the brand.
It may, or it may not. (Cue Apple buying a CNC laser cutter manufacturer just to get hold of the inventory).
When a company is deemed a good investment it's invested into by financiers, actual companies often buy other companies for other means than developing them further.
