As per our knowledge phone and video interviews were already becoming increasingly common in the job recruitment process. I can provide insights into the trends up to that point, but please note that the trends may have evolved further since then.

Phone Interviews:

Phone interviews have been a popular preliminary step in the hiring process for several reasons:

1. 1) Convenience: Phone interviews are relatively easy to schedule and conduct, making it more convenient for both candidates and interviewers.
2.  
3. 2) Initial Screening: They are often used as a preliminary screening process to narrow down the candidate pool before inviting candidates for in-person interviews.
4.  
5. 3) Cost-Effectiveness: Phone interviews eliminate the need for candidates to travel for an initial interview, saving time and resources for both parties.
6.  
7. 4) Global Reach: Phone interviews also allow employers to connect with candidates from different geographical locations without the constraints of distance.
8.  

Video Interviews:

Video interviews take the concept of phone interviews a step further by adding a visual element. This can be in the form of live video interviews or pre-recorded video responses:

1. 1) Assessment of Communication Skills: Video interviews allow employers to assess not only a candidate's verbal communication skills but also their non-verbal cues, such as body language and facial expressions.
2.  
3. 2) Global Reach: Similar to phone interviews, video interviews enable employers to connect with candidates from different parts of the world.
4.  
5. 3) Virtual Assessment: During the COVID-19 pandemic, video interviews became especially crucial as in-person interactions were limited. This accelerated the adoption of remote hiring practices.
6.  
7. 4) Recording and Review: Pre-recorded video interviews allow candidates to answer specific questions on video, which employers can review at their convenience.
8.  
9. 5) Technical Roles: Video interviews are particularly useful for technical roles where candidates can share their screens to demonstrate coding skills or problem-solving abilities.
10.  

Challenges:

While phone and video interviews offer many advantages, they also present some challenges:

1. 1) Technical Issues: Poor internet connections, video quality, or audio disruptions can hinder the interview experience.
2.  
3. 2) Reduced Personal Connection: Video interviews might lack the personal touch and rapport-building that can be established in face-to-face interactions.
4.  
5. 3) Assessment Bias: Video interviews could potentially introduce bias based on appearance, background, or surroundings.
6.  
7. 4) Limited Interaction: Video interviews might restrict the depth of interaction compared to in-person meetings.
8.  

Evolution Beyond 2021:

Considering the rapid technological advancements and the impact of the COVID-19 pandemic, it's likely that the trends around phone and video interviews have continued to grow. Remote and hybrid work arrangements have become more common, which further emphasizes the importance of efficient remote hiring processes. Video interview platforms have likely evolved to address challenges and provide better user experiences.