Some counselors take the position that counseling and friendship should not be mixed. The argument is that blending social relationships with professional ones simultaneously can negatively affect the therapy process, the friendship, or both. What are you ideas about this viewpoint?

In therapy, boundary crossings occur when professional and social inclinations are blended. However, boundary crossings need to be differentiated from boundary violations. While boundary crossings aren't necessarily illegal, boundary violations are.
According to the ACA Code of Ethics, boundary violations include the following:
Having a sexual relationship with a current client
Entering into a counseling relationship with a former lover, friends, or family members
Entering into a sexual relationship with a former client that results in harm to his/her wellbeing
Accepting or giving gifts to clients for manipulative purposes
Sexually harassing clients
Imposing personal values and beliefs on clients
Although boundary crossings may prove helpful in terms of patient welfare, they more often than not result in negative consequences. First, let's define boundary crossings. These can constitute any number of scenarios, such as:
Attending an event of great significance to a current client
Accompanying a current client to a radiation therapy session
Taking a walk with a client who suffers from debilitative depression
Recommending a good book that can provide a client therapeutic comfort
Basically, in and of themselves, boundary crossings aren't illegal. They only become illegal when they are exploitative in nature.
For example, a boundary crossing becomes exploitative when a therapist gives lavish gifts to clients in exchange for glowing recommendations (either word-of-mouth or online).
In the industry, many therapists assert that dual relationships (or boundary crossings) should be assiduously avoided. However, others maintain that boundary crossings can actually facilitate healing for the patient when incorporated into formal treatment plans.
If you choose to support the second thesis about boundary crossings, you must still approach boundary crossings in the context of these major points:
Setting: the location for therapy sessions, whether they be in a major metropolitan city or rural area. In rural areas, it may be impossible for the therapist and client to avoid seeing each other outside of a professional setting. In such cases, care needs to be taken to avoid confusion and complications.
Client history: does the client have a history of emotional trauma, sexual assault, or chronic illness?
Type of therapy: group versus individual, behavioral, cognitive, short-term versus long-term.
Therapist factors: age, culture, level of experience, and sexual orientation.
So, if a therapist chooses to allow a dual relationship with a client, the therapist must ensure that:
The interactions don't violate the ACA Ethics Code
All interactions are documented
Discussions about personal values and beliefs are avoided
All contact delivers beneficial, not harmful effects to the client
Interactions with the client are regularly evaluated
https://www.continuingedcourses.net/active/courses/course066.php

https://www.counseling.org/resources/aca-code-of-ethics.pdf

https://www.zurinstitute.com/boundaries-dual-relationships/