If I buy or build a robot "pet" that is programmed to act curious and friendly, and I personally derive pleasure from watching it and interacting with it, any sense of companionship I feel is legitimate, whether or not someone else wants to classify it as "love".
When it comes to robotic companions, the real thing to be wary of is whether or not it's actually your robot. An Alexa, for example, is a sales and marketing organ of Amazon, and any attempt at eliciting a sense of personality is in service of that device gathering information about you and using it to sell you stuff.
Twitter accounts for brands are not companions. The chatbot on your travel booking website is not a companion. Irrespective of any technology described as "AI" behind it, Alexa is structurally not a companion.